Objective To explore the risk factors of prognosis for children with acute kidney injury(AKI). Methods Clinical data of 118 children with AKI, including the causes, clinical characteristics, laboratory features, renal pathological findings, treatment and outcome, were reviewed retrospectively. Association between risk factors and prognosis was analyzed. AKI was defined by the new classification criteria of the Acute Kidney Injury Network. Prognostic factors were determined by univariate methods and stepwise multiple logistic regression analysis. Results One hundred and eighteen patients (83 male, 35 female) were enrolled in the study, who admitted in our department between January 1, 2005 and May 31, 2008. Median age at the time of AKI children was 7.5 years (range 1 day-14 years), among whom 28.0% (33 cases） was less than 3.0 years, 17.8% (21 cases) between 3.0 and 7.0 years and 54.2% (64 cases) more than 7.0 years. Patients’ AKI was classified according to the staging system as follows: 52.5% stage 1, 32.2% stage 2 and 15.3% stage 3. The common causes of AKI children were infectious and autoimmune diseases (39.8%), renal vascular disease (27.1%) and circulatory disturbance (11.9%). Hospital mortality was 21.2%. Multivariate analysis showed that independent risk factors for death were need for mechanical ventilation (OR=51.75, P＜0.01), sepsis/septic shock (OR=14.76, P＜0.01), severe acidosis(OR=11.38, P＜0.01), and white blood cells (WBC) count more than 20.0×109/L (OR=8.51, P＜0.01). Conclusion Infectious and autoimmune diseases, renal vascular disease and circulatory disturbance are the common causes of AKI children. The important risk factors of death in AKI children are need for mechanical ventilation, sepsis/septic shock, severe acidosis, and WBC count more than 20.0×109/L.

Objective To observe the long dwell ultrafiltration volume after using 7.5% icodextrin in different peritoneal transport characteristics of peritoneal dialysis patients. Methods Subgroup analysis of a perspective multicenter randomized double blind and parallel control study was performed. Continuous ambulatory peritoneal dialysis (CAPD) patients were divided into high transport (H) group, high-average transport (HA) group, low-average transport (LA) group and low transport (L) group according to D/Pcr and Twardoski standard. Ultrafiltration volume of night long dwell dialysate was calculated before and after clinic trial for 2 weeks and 4 weeks to evaluate the different effect of transporters on ultrafiltration volume. Results A total of 201 CAPD　patients were enrolled in the study, including 98 patients in icodextrin group (ICO group) and 103 patients in glucose group (GLU group). Male and female cases were 96 and 105 respectively. Age was (56.1±13.7) years old (range from 18 to 81). One hundred and ninety-eight patients finished peritoneal equilibrium test (PET), including 24 (12.1%) of H, 72(36.2%)of HA, 81(40.7%)of LA, and 21（11.0%）of L. After follow-up for four weeks, the ultrafiltration volume was much higher than baseline in H, HA and LA groups. Also ultrafiltration volume in icodextrin group was much higher than that in glucose-based dialysate. Howerve, the increased volume was not significantly difference in L group. Ultrafiltration volume of icodextrin was positively correlated to D/Pcr（R2=0.1681，P<0.01）, while ultratration volume of dextrose was negatively correlated to D/Pcr（R2=0.0949，P<0.01）. Conclusion Compare to glucose-based dialysate (Dineal), 7.5% icodextrin dialysate (Extraneal) improves the ultrafiltration and peritoneal creatinine clearance of long dwell notabily in H, HA and LA group.

Objective To study the relationship between periodontitis and chronic kidney disease (CKD) among Uygur adults of Xinjiang. Methods Data of 1650 Uygur adult residents (age>18 years) in the Moyu county, Xinjiang were analyzed. The subjects were sampled randomly with stratify capacity from 15 villages among 364 villages. All the subjects received the questionnaire and the oral examination. The markers and risk factors of chronic renal injury were inspected. The subjects were categorized as periodontitis group and non-periodontitis group according to chronic periodontitis diagnostic criteria. The periodontitis group was further divided into mild, moderate and severe periodontitis. Results The data of 1415 subjects were completed. The prevalence of chronic periodontitis was 65.2％ (95％CI：65.0-65.4). The prevalence of CKD was 5.2% (95％CI：5.1-5.3). Albuminuria was found in 4.2% (95％CI：4.1-4.3) of subjects. 1.3% (95％CI：1.3-1.4) of individuals had renal insufficiency. In periodontitis group, the prevalence of CKD was 6.4%, which was higher than that in non-periodontitis group 2.9% (χ2=7.841，P=0.005). Univariate regression analysis showed that severe periodontitis was risk factor of CKD（OR=3.2, 95%CI:2.0-5.2）. Multivariate logistic regression analysis showed that severe periodontitis was independently associated with CKD (OR=1.9, 95%CI:1.1-3.3). Conclusions In Uygur adults of rural area of Xinjiang, the prevalence of CKD is higher in periodontitis group as compared to non-periodontitis group. Severe periodontitis is an independent risk factor of CKD.

Objective To evaluate the contrast-enhanced ultrasonography (CEUS) in quantitative diagnosis of chronic renal insufficiency. Methods Correlation of CEUS indexes with glomerular filtration rate (GFR) detected by 99mTc-DTPA renography was examined. Thirty-three cases of clinical chronic renal insufficiency were enrolled in the study. They were 15 males and 18 females with average age of (43.33±6.78) years. After intravenous bolus injection of 1 ml SonoVue, CEUS of renal cortex blood perfusion was performed successfully, and a time-intensity curve (TIC) was created with PHILIPS iU22 system’s QLAB software. A 148 to 222 MBq dose of 99mTc-DTPA was injected as a bolus from antecubital vein. Renal scintigraphic images were collected immediately and GFR was obtained. Results The significant correlation coefficients between GFR and CEUS quantitative indexes were as follows: rAUC (area under curve)=0.886 (P<0.05), rA (slope rate of ascending curve, A) =0.804(P<0.05). However, rDPI (derived peak intensity, DPI）= 0.021 (P>0.05), rTTP (time to peak, TTP) =0.043 (P>0.05), rα (slope rate of descending curve, α)=0.039 (P>0.05). Conclusion CEUS can precisely display the hemodynamic change of chronic renal insufficiency, which is well correlated with GFR by 99mTc-DTPA renography.

Objective To analysis if interleukin-1β（IL-1β） can regulate human mesangial cells （HMC） to uptake oxidized low density lipoprotein （Ox-LDL） and if the effect of IL-1β be changed through the lectin-like oxidized low-density lipoprotein receptor 1（LOX-1） pathway. Methods The uptake of HMC to Ox-LDL stimulated by IL-1β was observed using Oil Red “O” and flow cytometry. The level of LOX-1 in HMC induced by IL-1β and Ox-LDL was examined using real-time PCR and Western blotting. Results Uptake of Ox-LDL and Dil-Ox-LDL by HMC was up-regulated upon stimulation with IL-1β in a dose- and time-dependent manner. Intracellular mean fluorescence density of Dil-Ox-LDL with LOX-1 blocker in IL-1β stimulation group was decreased compared to that without blocker. The peak level of LOX-1 mRNA reached after 6 h of stimulation and was as high as 6.87-fold of control. IL-1β could induce LOX-1 mRNA expression in a dose-dependent manner. Treated with 10 μg/L IL-1β for 12 h, the up-regulation effect on LOX-1 mRNA was as high as 6.57-fold of control. IL-1β could induce LOX-1 protein expression in a time- and dose-dependent manner. The peak level of LOX-1 protein reached after 24 h of stimulation of 5 μg/L IL-1β and was as high as 1.88-fold of control. Treated with 10 μg/L IL-1β for 24 h, the up-regulation effect on LOX-1 protein reached peak and was as high as 2.57-fold of control. IL-1β could induce LOX-1 mRNA and protein expression in a dose-dependent manner. Conclusion The expression of LOX-1 can be up-regulated by IL-1β in a dose-dependent manner and the enhanced uptake of HMC to Ox-LDL stimulated by IL-1β partly through the LOX-1 pathway, which means the dyslipidemia of HMC can be enhanced by inflammatory cytokines.

Objective To explore the effect of soluble tyrosine kinase 2 fusion protein (sTie-2-Fc) on peritoneal angiogenesis, solute transport and ultrafiltration capacity in uremic rats undergoing peritoneal dialysis (PD). Methods Thirty-two male Wistar rats were randomly divided into sham-operation group, uremic group, uremic PD group, and sTie-2-Fc group (all n=8). Uremic PD group and sTie-2-Fc group received intraperitoneal infusion of 3 ml/100 g of peritoneal dialysis fluid (PDF) containing 4.25% glucose twice daily for 4 weeks. Rats in sTie-2-Fc group were infused with PDF supplemented with 1 μg sTie-2-Fc. Before the rats were sacrificed, a peritoneal equilibration test (PET) was performed to evaluate the peritoneal solute transport and ultrafiltration capacity, and omenta was obtained for anti-CD31 immunohistochemical staining to determine the vessel density. Results Compared to their counterparts in sham-operation group, rats in uremic group had higher 2 h-dialysate to plasma creatinine concentration ratio (D/Pcr, 0.78±0.05 vs 0.70±0.09, P=0.028), lower 2 h to initial dialysate glucose concentration ratio (D/D0, 0.69±0.05 vs 0.76±0.07, P=0.033), decreased peritoneal ultrafiltration [UF, (2.29±0.50) ml vs (4.58±1.64) ml, P=0.005], and increased omental vessel density [(5.8±3.0)/HP vs (1.6±0.5)/HP, P<0.01]. When compared to uremic group, rats in uremic PD group showed higher D/Pcr (0.89±0.05 vs 0.78±0.05, P=0.001), lower D/D0(0.47±0.09 vs 0.69±0.05, P<0.01), decreased UF[(0.40±0.59) ml vs (2.29±0.50) ml, P=0.005] and more omental vessels [(16.7±1.2)/HP vs (5.8±3.0)/HP, P<0.01]. Improved peritoneal UF [(1.56±0.48) ml vs (0.40±0.59) ml, P=0.014] and decreased omental vessels[(9.2±1.2)/HP vs (16.7±1.2)/HP, P＜0.01] were observed in rats treated with sTie-2-Fc compared with those in uremic PD group, however, the differences of D/Pcr (0.87±0.06 vs 0.89±0.05, P=0.122) and D/D0 (0.60±0.11 vs 0.47±0.09, P=0.06) between these two groups did not reach statistical significance. Conclusion sTie-2-Fc preserves peritoneal ultrafiltration capacity and ameliorates peritoneal angiogenesis caused by uremia and exposure to bioincompatibal PDF.

Objective To explore the effect of hypoxia inducible factor-1α silencing by siRNA on proliferation, apoptosis and necrosis of human renal proximal epithelial cell ( HK-2 ) under hypoxia. Methods CoCl2 was used to mimic hypoxia, and siRNA technique was used to silence HIF-1α. HK-2 cells were divided into five groups, including normal culture group, hypoxia culture group, transfection reagent group, negative control group and HIF-1α siRNA group. MTT assay was used to detect the growth inhibition ratio of cells. TUNEL and caspase-3 quantity was used to detect apoptosis. LDH activity in supernatant was detected to evaluate cell necrosis. Real-time PCR and Western blotting were used to detect mRNA and protein of HIF-1α, HIF-2α, glucose transporter 1(Glut-1) and vascular endothelial growth factor (VEGF). Results (1) The transfection efficiency of siRNA was 95%-100%. Under normoxia, the efficiency of siRNA silencing HIF-1α gene reached to 70%, while under hypoxia, it was 97%. (2) The growth inhibition ratio of cells in HIF-1α siRNA group was significantly higher than that of other groups including hypoxia culture group, transfection reagent group and negative control group (all P<0.05). No significant difference was found in apoptotic ratio of the other four groups except normal culture group (P>0.05). The LDH level in HIF-1α siRNA group was significantly higher than that of hypoxia culture group, transfection reagent group and negative control group (P<0.05). (3) The expression of HIF-1α, Glut-1, VEGF mRNA and protein in HIF-1α siRNA group was significantly lower than that of hypoxia culture group, transfection reagent group and negative control group (P<0.05). No significant difference was observed on the level of HIF-2α mRNA and protein in the other four groups except normal culture group (P>0.05). Conclusion HIF-1α gene silencing can inhibit the mRNA and protein expression of Glut-1 and VEGF, and can aggravate growth inhibition and necrosis of HK-2 cells under hypoxia.

Objective To investigate whether erythropoietin(EPO) can inhibit the pro-apoptotic effect of high glucose on rat proximal tubular epithelial cells, and the possible mechanisms in which EPO exerts its anti-apoptotic role. Methods Rat proximal tubular epithelial cells (NRK-52E) were divided into 5 groups: normal control group, osmolarity control group, high glucose group, high glucose with EPO (50 U/ml) group and high glucose with EPO (100 U/ml) group. The expression of EPO receptor(EPOR) in NRK-52E cells was examined by immunocytochemistry. The effect of high glucose on the expression of EPOR was detected by Western blotting. The rate of apoptosis was evaluated by flow cytometry Annexin V-FITC/PI double stains. The intracellular ROS was detected using fluorescent probe CM-H2DCFDA. The expression of bcl-2, bax and caspase-3 mRNA were examined by RT-PCR. Results The expression of EPOR was demonstrated in NRK-52E cells, and high glucose could up-regulate the expression of EPOR. High glucose could induce oxidative stress in NRK-52E cells, and up-regulate the mRNA expression of bax and caspase-3, down-regulate the mRNA expression of bcl-2. These effects of high glucose on NRK-52E cells could be reversed by EPO. Conclusion EPO inhibits NRK-52E cells apoptosis induced by high glucose through attenuating oxidative stress,up-regulating the expression of bcl-2 mRNA and down-regulating the expression of bax and caspase-3 mRNA, which may be mediated by EPOR.

Objective To determine the differentially expressed genes in the development of vascular medium calcification in rats using the suppression subtractive hybridization (SSH). Methods Twenty-four 6-week old SD rats of specific pathogen free grade were recruited and randomly allocated into calcified group (n=12) and control group (n=12). Rats were made for vascular calcification model in calcified group(vitamin D3 plus nicotine, VDN). All rats were sacrificed to measure concentration of calcium in the arterial tissue and examine the pathological lesion changes. RNA in rat aortic tunica tissue was extracted and reverse transcripted into cDNA. cDNA fragments which highly expressed calcification were isolated in calcified group using the SSH. Differentially expressed genes with cDNA fragment were inserted into PMD18-T plasmid vector and transformed to competent DH-5α by means of heating transfer. cDNA libraries of differentially expressed gene between calcified group and control group were successfully constructed. Recombinant vectors were analyzed by colony PCR. Positive genes were randomly selected for sequencing and analyzed by BLAST. Six genes, for example, were randomly selected for RT-PCR certification. Results (1) The pathological examination results demonstrated that in calcified group there were obvious calcium diposits and media squirm in tunica media of rat aortic wall, while in control group no calcium diposit was found. (2) There was statistical significance in calcium concentration in vascular tissue between calcified group[ (15.34 ± 2.51)mg/g] and control group [(5.20 ± 0.75) mg/g ] (P<0.01). (3) Subtracted libraries in vascular calcification was successfully established. Ninety-two positive clones in positive library and 18 positive clones in reverse library were obtained after the colony PCR identification. The length of insertion fragments was concentrated between 150 bp and 400 bp. Calcification-related 43 up-regulated genes and 11 down-regulated genes were obtained through sequencing and BLAST analysis in positive clones. RT-PCR validation indicated that the expressions of 5 genes such as CytoP450 and Nell1 had greater increase in calcified group than those in control group, the average fold change was 1.71. Conclusions Model of vascular calcification induced by vitamin D3 plus nicotine is successfully constructed. Related gene expression spectrum is changed in the process of vascular calcification. Some ossification genes and genes associated with apoptosis, oxidation, inflammation and cytokines are up-regulated. At the same time, some genes which possibly inhibit vascular calcification are down-regulated.

Objective To investigate the clinical and renal pathological features in the new rat model induced by anti-human podocyte-protein antibody. Methods The rat model was induced by once intravenous injection of rabbit anti-human podocyte-protein antiserum which was prepared at first. Male Sprague-Dawley rats (n=36) were randomly divided into six groups (6 rats in each group): control group (CG), the time points of day 7 group (D7), day 14 group (D14), day 21 group (D21) and day 28 (D28) group after antiserum injection, and day 28 group after the normal rabbit serum injection (NRG). The level of 24 hour proteinuria, the clearance of creatinine, albumin, blood urea nitrogen, triglyceride, cholesterol and serum creatinine were measured. The renal morphology was detected under the light microscope, immunofluorescence microscope, and electron microscope. Results 24-hour proteinuria (mg) was gradually increased, and the level of proteinuria in D28 (48.56±13.80) was significantly higher than that in CG (5.34±2.77, P<0.01) and NRG (11.32±4.90, P<0.01). The clearance of creatinine (ml/min) and serum creatinine (μmol/L) in D28 (0.90±0.47, 33.48±9.94) were significantly different from CG (1.68±0.54, P<0.05; 26.03±2.67, P<0.05), but showed no difference with NRG (1.34±0.87, P>0.05; 27.40±4.73, P> 0.05). The level of albumin (g/L) was lower in D7, D14, D21, D28 (28.20±0.87, 27.80±1.97, 27.42±1.66, 27.77±1.95) than CG (29.98±0.76, P<0.05). But there was no difference in the level of albumin among the groups after antiserum injection and NRG (28.68±1.18, P>0.05). The level of blood urea nitrogen, triglyceride, cholesterol showed no difference among the groups (P>0.05). The renal morphology showed no obvious changes between CG and NRG. Among the groups after antiserum injection, the renal pathological changes under the light microscope were some spikes formation in D28. Immunostained for rabbit IgG in rat glomeruli progressively decreased over the 28 days, while rat IgG progressively increased. The renal section deposition for rat complement 3 reached a maximum at day 21 then decreased afterward. Under the electron microscope, there were immune complexes and foot process fusion at day 14. Conclusions The new rat model induced by anti-human podocyte-protein antibody showing typically clinical and pathological changes of the membranous nephropathy is successfully established.