Different expression levels of exosomal miR-503 in peritoneal dialysis effluent from patients of different peritoneal transport characteristics and bioinformatics analysis / 中华肾脏病杂志

Objective:To compare the expression level of exosomal miR-503 in peritoneal dialysis effluent (PDE) from patients of different peritoneal transport characteristics, predict the target genes of miR-503 and provide bioinformatic data for researches of peritoneal transport characteristics.Methods:Twenty-four stable peritoneal dialysis (PD) patients were selected and divided into high transport group (H group, n=12) and low transport group (L group, n=12) according to the results of peritoneal equilibration tests (PET). The 500 ml PDE that was left on the patient's abdomen overnight was collected and concentrated using ultrafiltration cell. Exosomes in PDE were resuspended in phosphate buffered saline (PBS) after ultracentrifugation and the characteristics of PDE exosomes were identified by transmission electron microscope (TEM), nanoparticle tracking analysis (NTA), Western blotting and fluorescent staining. MicroRNAs were extracted from PDE exosomes. The expression levels of PDE exosomal miR-503 in the two groups were detected by quantitative real-time PCR. Then the relations between the relative quantity of PDE exosomal miR-503 and PET values or 24 h ultrafiltration volume (UF) were analyzed. Targetscan and miRDB databases were used to predict the target genes of miR-503. Gene ontology (GO) functional enrichment and Kyoto encyclopedia of genes and genomes (KEGG) signaling pathway analysis were relied on DAVID (https://david.ncifcrf.gov/). Results:The exosomes in PDE showed a round and cup-shaped morphology under TEM, and the diameters were approximately 100 nm measured by NTA. The specific biomarkers of exosomes, CD63, CD81 and heat shock protein -70 (HSP-70) were all detected by Western blotting. The internalization and uptake of the exosomes was observed after fluorescent staining. The relative expression level of PDE exosomal miR-503 in H group was found to be significantly higher than that in L group ( P=0.002), and the relative quantity of PDE exosomal miR-503 was significantly positively correlated with PET values ( r=0.547, P=0.006), but not 24 h UF ( r=-0.297, P=0.159). There were 156 target genes of miR-503 in total that could be predicted by two different databases at the same time. GO analysis of these 156 target genes was mainly focused on kinase binding, regulation of protein modification and catabolic process as well as regulation of epithelial cell proliferation. KEGG enriched many tumor associated or classical signaling pathways, including transforming growth factor-β (TGF-β) signaling pathway and vascular endothelial growth factor (VEGF) signaling pathway. The prediction showed that vascular endothelial growth factor A (VEGFA) was a direct target gene of miR-503 and it was also related to many proteins involved in fibrosis mechanism. Conclusions:The expression level of PDE exosomal miR-503 is significantly higher in H group, and positively correlates with PET values, which may regulate the angiogenesis of peritoneal vessels by targeting VEGFA.

Correlation analysis of coronary artery calcification score and prognosis of peritoneal dialysis patients / 上海交通大学学报（医学版）

Objective · To estimate correlation between coronary artery calcification score (CaCS) and prognosis of peritoneal dialysis (PD) patients.Methods · The clinically stable patients who had undergone PD for at least 2 months were recruited for this prospective and observational cohort study.Coronary artery calcification was assessed by multislice spiral computed tomography and was recorded according to the Agatston score. The patients were assigned to 3 groups, i.e. no calcification group (CaCS=0), low calcification group (0

Changes of serum leptin levels and the influential factors in peritoneal dialysis patients / 中华肾脏病杂志

Objective To investigate the changes of serum leptin levels and the influential factors in maintenance peritoneal dialysis patients.Methods Seventy-six peritoneal dialysis patients were chosen at the time before,and 3 months,6 months,12 months,18 months and 24 months after they began the peritoneal dialysis therapy,to examine body mass index (BMI),triceps skinfold thickness (TSF),abdominal circumference,homeostasis model assessment of insulin resistance (HOMA-IR),the plasma lipid profile,and leptin in the same situation.Results For 24 months,these patients showed higher serum leptin level than the values before commencing peritoneal dialysis treatment (P ＜ 0.01).The level of leptin was positively correlated with the BMI(r =0.412,P ＜ 0.01),TSF(r =0.308,P ＜ 0.01),abdominal circumference(r =0.284,P ＜ 0.01),HOMA-IR(r =0.184,P ＜ 0.01) and TG(r =0.288,P ＜ 0.01),negatively corelated with the high-density lipoprotein cholesterol(HDL-C)(r =-0.285,P ＜ 0.01).Multiple logistic regression analysis showed that BMI (β =0.339,P ＜ 0.01),TGβ =0.157,P ＜ 0.01) and HDL (β =-0.126,P ＜ 0.05)were significant predictive factors for the changes of serum leptin levels.Conclusion Leptin maybe involve in the occurrence and the development of cardiovascular events like other metabolic parameters in peritoneal dialysis therapy.

Empiric initial therapy in peritoneal dialysis-related peritonitis / 中华肾脏病杂志

Objective To investigate the pathogens,drug resistance and outcomes of continuous ambulatory peritoneal dialysis(CAPD) patients with peritoneal dialysis-related peritonitis in our peritoneal dialysis(PD) centers. Method Data including clinical manifestations,pathogens,treatment,outcome of 93 CAPD cases with peritoneal dialysis-related peritonitis in our peritoneal dialysis(PD) centers were retrospectively analyzed.Results Dialysate culture of 75cases was positive with a positive rate of 80.2％,including 45 cases of gram-positive cocci,21cases of gram-negative bacilli,2 cases of fungi and 5 cases of mixed infection.Coagulase-negative staphylococci were the most common gram-positive cocci.All the gram-positive cocci were sensitive to vancomycin,but the resistance rate to cefazolin was 60.0％ with an increasing tendence year by year.Resistance rate of gram-negative bacilli to ceftazidime was 46.1％.All the gram-negative bacilli were sensitive to imipenem.The withdraw rate of CAPD was 17.2％(16/93) because of peritonitis. Noobviousside-effectofperitonealadministrationofvancomycinwasfound.Conclusions Gram-positive cocci are major pathogens in CAPD-related peritonitis.Now cefasolin is not suitable for the empiric initial treatment.Peritoneal administration of vancomycin should be recommended for peritonitis caused by gram-positive cocci.

Clinical analysis of early diagnosis of lumbar spondylotic myelopathy / 中国组织工程研究

Objective To probe into the feasibility of early diagnosis of lumbar spondylotic myelopathy(LSM)prospectively and to screen the premorbid signs of LSM clinically, radiologically. Method Thirty items related to the occurring of LSM were chosen as common characteristics of LSM and considered as the criteria of prospective study. 236 patients who met the criteria were studied. All patients were divided into three groups and followed up and observde for 2～10 years (mean 4. 3years), every item of each group was compared and analyzed. Result Sixty - eight patients showed LSM during investigation. Sixteen items of the criteria were related to the occurring of LSM. The significant items include lower limb pain and abnormal sensation limb numbness, lumbar canal stenosis, lower lumbar instability, lumbar intervertebral disk herniation, and delay of central motor conduct time. Conclusion LSM can be early diagnosed. The patients who meet the established criteria should be followed up and observed closely.

Expression of channel protein mRNA in kidney of congestive heart failure and its significance / 中华肾脏病杂志

Objective To investigate the expression of renal aquaporin 2 (AQP2), epithelial sodium channel (ENaC) and kidney specific Na-K-2Cl cotransporter (rBSC1) in the thick ascending limb of Henle in different kinds of congestive heart failure rats. Methods To establish different congestive heart failure animal models with abdominal aortocaval shunts (1 pore and 3 pores) and ligature of the left coronary artery respectively in SD rats. Cardiac function was tested with Doppler echocardiography. The amount of renal AQP2, ENaC and rBSC1 mRNA was measured using semi-quantitative RT-PCR. Results Cardiac function of aortocaval shunt rat deteriorated to a lesser extent. While cardiac function of ligation rats was severely decompensated. AQP2 mRNA was enhanced only in renal cortex in ligation group. While rBSC1 was up-regulated significantly both in aortocaval shunt rat and ligation rat. In renal cortex, the amount of ENaC increased remarkably in all three congestive heart failure groups, while in medulla, the significant increasing in ENaC expression was only found in ligation rat. Conclusions Renal AQP2, ENaC and rBSCl mRNA enhance to different extent in different kinds of congestive heart failure animal models. There is probably a correlationship between the upregulation of rBSC1 mRNA and impaired renal sodium excretion in early phase of cardiac lesion.

Study on the antioxidative effect of losartan at increasing dose in diabetic nephropathy / 中华肾脏病杂志

Objective To understand the situation of oxidative stress among diabetic nephropathy (DN) patients and observe the antioxidative effect of losartan at increasing dose in DN patients. Methods Thirty type 2 DN patients who neither smoked and nor took antioxidants were selected. The study began with an initial 4-6 weeks screening-treatment. Eligible patients then received losartan 50 mg/d daily for 8 weeks followed by losartan 100 mg/day daily for an additional 8 weeks. Blood glucose and blood pressure were closely monitored over the whole study period. All patients were followed up every other weeks, their 24-hour urine samples,fresh urine and venous blood sample were collected to measure urinary protein and creatinine excretion, urinary 8-OHdG, SOD, TAOC and MDA excretion , serum SOD, TAOC , MDA and other blood biochemistry parameters. Urinary 8-OHdG was determined by capillary electrophoresis and liquid phase chromatography. Results The total 24 hours urinary 8-OHdG excretion and the serum MDA concentration were higher than the normal values. The serum and urine SOD concentrations were lower than the normal values. There was an improvement in urinary 8-OHdG,serum and urine SOD, serum and urine MDA levels with losartan therapy. Compared with losartan 50 mg/d, the antioxidative effect of losartan 100 mg/d was more noticeable. Obvious decrease in 24-hour proteinuria on exposure to losartan was found, without severe adverse effect. Conclusions Oxidative stress damage is active in DN patients. Losartan has antioxidative effect on DN patients. Compared with losartan 50 mg/d, the antioxidative effect of losartan 100 mg/d is more marked, without increasing side effect. Losartan's antioxidative effect may be involved in its beneficial mechanisms on DN.