Effect of calcium phosphate crystals induced by uremic serum on calcification of human aortic smooth muscle cells / 中华肾脏病杂志

Objective To investigate the impact of calcium phosphate crystals induced by uremic serum on calcification of human aortic smooth muscle cells (HASMCs).Methods Uremic serum was incubated at 37℃ for 3 days.Calcium phosphate crystals and uremic supernatant were isolated from uremic serum by uhracentrifugation.Scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX) were performed for analysis of morphological and chemical characteristics of the crystals.HASMCs were treated in vitro with control medium,uremic serummedium,calcium phosphate crystals-medium and uremic supernatant-medium.Calcification was visualizcd by Alizarin red staining.Calcium loads in cells were quantified by o-cresolphthalein complexone method.Gene expression of bone morphogenetic protein-2 (BMP-2),osteopontin (OPN) and core-binding factor α1 (Cbfα1),alkaline phosphate (ALP) and matrix gamma carboxyglutamic acid protein (MGP) were quantified by real-time PCR.Cbfα1,OPN and BMP-2 protein levels were determined by Western blotting or ELISA.Results Calcium phosphate crystals which induced by uremic serum displayed laminated shapes containing crystallized needle-like projections and ranged from 30-500 nm,with Ca/P ratios of 1.41 ±0.05.Compared with the cells in control group,uremic serum induced HASMCs calcification,increased calcium loads (P ＜ 0.05),up-regulated BMP-2,OPN,Cbfα1 mRNA and protein expression (all P＜ 0.01).Similar to uremic serum,calcium phosphate crystals also induced HASMCs calcification,increased calcium loads (P＜0.05),and up-regulated BMP-2,OPN,Cbfα1 mRNA and protein expression (all P ＜ 0.01).However,there was no significant difference between HASMCs growing in uremic supernatant and control medium in calcium loads or the expression levels of these osteogenic proteins (P ＞ 0.05).Conclusions Calcium phosphate crystals induced by uremic serum promote HASMCs calcification,which might be one of the mechanisms of uremic vascular calcification.

Prognostic comparison of patients starting peritoneal dialysis within two weeks and more than two weeks after catheter implantation / 中华肾脏病杂志

Objective To compare the outcomes of patients starting peritoneal dialysis (PD)within two weeks and more than two weeks after catheter implantation.Methods All the patients undergoing Tenckhoff catheter implantation and initiating PD in Renji Hospital from January 2001 to December 2010 were enrolled in the study.Patients started PD within 2 weeks after catheter insertion were defined as urgent group,and those started PD 2 weeks later were defined as planned group.Kaplan-Meier curves and Log-rank tests were used to compare outcomes between two groups.Results Among 657 patients in this study,median break-in period was 6 days of 469 (71.4％)patients in urgent group and 26 days of 188 (28.6％) patients in planned group.Compared to planned group,patients of urgent group were younger [(52.6± 17.3) vs (56.1± 15.3) year,P =0.017],had less eGFR [(5.36±2.03) vs (6.50±2.50) ml· min-1 · (1.73 m2)-1,P ＜ 0.01],lower serum albumin [(34.0±5.7) vs (36.2±5.9) g/L,P ＜ 0.01] and hemoglobin [(76.9± 18.8) vs (80.8 ± 17.9) g/L,P =0.018],and higher phosphate [(2.19±0.67) vs (1.98±0.52) mmol/L,P＜ 0.01].Urgent group presented more catheter dysfunctions needed to transfer to hemodialysis (2.1％ vs 0％,P =0.044).The 1-,2-,3-and 5-year technique survival rates of urgent and planned group were 94％ vs 98％,92％ vs 94％,90％ vs 92％and 86％ vs 85％ respectively.There was no significant difference in technique survival (Log-rank =1.536,P =0.22) and peritonitis-free survival (Log-rank =0.035,P =0.85) between two groups.The 1-,2-,3-and 5-year patient survival rates of urgent and planned group were 90％ vs 95％,81％ vs 90％,74％ vs 79％ and 67％ vs 74％ respectively,and no significant difference was found (Log-rank =2.364,P =0.12).Conclusions Although patients needing urgent initial PD have poorer residual renal function and nutritional condition compared to those of planned initial PD,their outcomes are similar.Peritoneal dialysis may be a feasible and safe dialysis modality for patients who need urgent start.

Soluble tyrosine kinase 2 fusion protein ameliorates peritoneal morphologic and functional changes in uremic peritoneal dialysis rats / 中华肾脏病杂志

Objective To explore the effect of soluble tyrosine kinase 2 fusion protein (sTie-2-Fc) on peritoneal angiogenesis, solute transport and ultrafi]tration 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) mi, 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) mi, 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.

Great influence of peritoneal transport characteristics on ultrafiltration of icodextrin / 中华肾脏病杂志

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.

Association of peritoneal angiogenesis with angiopoietin-2 in peritoneal dialysis rats / 中华肾脏病杂志

Objective To investigate the association between angiopoietin-2 (Angpt-2) and peritoneal angiogenesis in a uremic peritoneal dialysis (PD) rat model. Methods Uremic (subtotal nephrectomy) rats were established and divided into non-PD, 10 d-PD, 28 d-PD and 56 d-PD groups. Standard PD solution was applied in the study. Rats undergone sham operation without PD were used as control group. Vessel density of the peritoneum was detected and quantified with anti-CD31 immunohistochemical staining. Expressive levels of Angpt-2 and vascular endothelial growth factor (VEGF) were examined in the peritoneum by real-time PCR and Western blotting. Results The non-PD group was characterized by increased vessel density in the peritoneum compared with that of the control group [(5±3)/HP vs (1±1)/HP]. Progressive angiogenesis was found in 10 d-PD, 28 d-PD and 56 d-PD groups [(10±5)/HP, (17±5)/HP, (19±4)/HP]. Furthermore, expressive levels of Angpt-2 and VEGF increased significantly in the non-PD group compared with the control (P<0.01), and such expressions were significantly higher in the PD groups as compared to non-PD group (P<0.01), but no difference was found among the PD groups. Both VEGF and Angpt-2 levels were positively correlated with vessel density(r=0.7756, P<0.01; r=0.5223, P<0.05). Conclusions Uremia and PD promote peritoneal angiogenesis in rats. Increased expression level of Angpt-2 in peritoneum is positively correlated with peritoneal angiogenesis. Angpt-2 may be a new therapeutic target of peritoneal angiogenesis.

Characteristics of long-term survivors on peritoneal dialysis / 中华肾脏病杂志

ObjectiveTo evaluate the characteristics of patients on long-term peritoneal dialysis (PD). MethodsPatients who started PD since 1994 and received PD for at least one year were included in this study. According to dialysis duration, patients were divided into two groups. Group A (long-term) was defined as patients survived on PD for more than 5 years. Group B (short-term) was defined as patients who died or switched to bemodialysis within less than 5 years. Demography, biochemical indexes, dialysis prescription and adequacy were compared between two groups. ResultsThere were 68 patients in group A and 98 patients in group B. Mean followed-up period of group A and B was (84.80±19.42) months and (27.25±12.31) months, respectively. Younger, fewer episodes of diabetic comorbidity (group A 3/68 vs group B 18/98, P ＜0.05) and coronary heart disease (group A 6/68 vs group B 22/98, P＜0.05) were found in group A. Compared to group B, the level of serum albumin at the beginning of PD was much higher in group A [(35.56±4.74) g/L vs (33.69±5.45) g/L, P＜0.01). The levels of blood sugar, TC, TG, hemoglobin, calcium, phosphate and iPTH were not significantly different between two groups. Estimated GFR, renal Kt/V and renal Ccr at the beginning of dialysis were much higher in group A, however there was no significant difference in urinary volume between two groups. Both estimated GFR and urinary volume decreased more slowly in group A compared to group B. Peritonitis mobidity was lower in group A (1/81.22 months vs 1/29.03 months, P＜0.01). Conclusions In comparison to short-term survivors, long-term PD patients are characterized by being younger, less diabetic and coronary heart disease, fewer episodes of peritonitis, higher level of serum albumin, higher estimated GFR and less loss of residual renal function.

Comparison of relative blood volume changes in dialysis-symptomatic hypotension and dialysis-refractory hypertension during hemodialysis / 中华肾脏病杂志

Objective To investigate and compare relative blood volume (RBV) changes in dialysis-symptomatic hypotension and dialysis-refractory hypertension during hemodialysis. Methods Fifteen patients with dialysis-symptomatic hypotension (SH group) and thirteen patients with dialysis refractory hypertension (RH group) on chronic haemodialysis were enrolled in this study. RBV, blood pressure, heart rate and ultrafiltration volume (UV) were measured before hemodialysis and at 1 hour intervals during hemodialysis. Total of 149 and 146 five-hour hemodialysis sessions were performed separately. RBV was assessed using Automatic Blood Volume Monitor. Results RBV changes were significantly higher in SH group than in RH group (P

Practical application of modified peritoneal equilibrium test in peritoneal dialysis patients / 中华肾脏病杂志

Objectives To investigate the practical application of modified peritoneal equilibration test (modified PET) employing 4.25% glucose exchange in peritoneal dialysis patients and to assess the reference values and clinical significance of the test. Methods Modified PETs were performed in 97 patients without peritonitis for at least 4 weeks. Mass transfer area coefficient (MTAC) was calculated according to the Garred model. Creatinine D/P concentration ratio at 4 hr (4 h D/Pcr), sodium D/P concentration ratio at 1 hr (1 h D/PNa+) and net ultrafiltration (nUF) were also assessed. Ultrafiltration 0.05). 4 h D/Pcr and MTACcr of modified PET were significantly correlated with 4h D/Pcr of standard PET (P

Analysis of clinical outcome in long-term peritoneal dialysis patients / 中华肾脏病杂志

Objective To analysis the clinical outcomes in long-term peritoneal dialysis (PD) patients. Methods The data of 58 PD patients survived more than 3 years from January 1994 to August 2003 in our hospital were reviewed. According to their different clinical outcomes, the patients were divided into four groups:continuous PD group, transplant group,hemodialysis (HD) group and death group. The recent nutritional index, such as serum albumin, and the recent dialysis adequacy index, including fluid removal and residual renal function, were evaluated. The "predeath values" of 1/2 year and 1 year prior to death in the death group were compared. 12-month PD indices in continuous PD patients were reviewed retrospectively and the same indices over a 12-month period of time were followed up. Results The recent total Kt/V in death group was significantly lowered than that in the other three groups (P

Re-evaluation of solute transport groups of peritoneal dialysis patients using peritoneal equilibration test / 中华肾脏病杂志

Objective To clarify whether the peritoneal equilibration test (PET)-determined solute transport groups defined by Twardowski fits patients in our medical center. Methods 158 initial standardized PET data since 1995 was selected and proportions of four transport groups were calculated according to Twardowski's criterion. Using the mean and standard deviations of 4-hour dialysis/plasma ratio of creatinine (D/Pcr), transport groups of our patients were re-determined. Patients were classified as follow: according to both two criteria, patients whose 4-hour D/Pcr in the range of high transport, low transport and average transport were classified as group H1, group L1 and group A, respectively; several average transport patients who changed to low transport after re-evaluation were classified as group L2; high transport patients who changed to average transport were classified as group H2. Every group was compared with clinical status in order to evaluate which criterion fit our patients. Results The 4-hour D/Pcr was 0. 70 ?0. 14 in our patients. The proportion of high, high-average, low-average and low transport were 21.5%, 44.9%, 17.8% and 5. 7% according to Twardowski's and 14. 6% , 33.5%, 33.5% and 18. 4% after re-evaluation. The ultrafiltration volume in group L2 was significantly higher than that in group A ( P

Bacteria spectrum and prognosis of exit-site infection in peritoneal dialysis patients / 中华肾脏病杂志

Objective To investigate the bacteria spectrum and prognosis of exit-site infection in peritoneal dialysis patients. Methods Perfect exit, equivocal exit, exit-site infection (ESI) and tunnel infection (TI) were classified. Incidence of ESI, bacteria spectrum, treatment effect and prognosis were statistic. Results Sixty-nine patients' exits were examined monthly, twenty-one episodes of ESI were occurred during eighteen months. Main pathogens of exit-site infection were staphylococcus aureus (47. 6% ) and pseudomonas aeruginosa(28. 6% ) . Seventeen episodes of ESI were cured. Four episodes of ESI accompanied with tunnel infections. TI rate diagnosed by clinical observation and ultrasound was 0. 012/patient-year and 0. 036/patient-year respectively. Conclusions The outcome of catheters is associated with the regiment of bacteria. Tunnel infection often occurs in whom with a long time exit-site infection. Ultrasound examination can clarify the diagnosis simply and quickly.