Objective To improve the cognition of long-term indwelling venous catheter in placement, management and nursing, and to prolong the use of catheter. Methods General status and complications of 380 long-term indwelling venous cuffed catheters in 355 maintenance hemodialysis patients were followed up. The reasons of ending or survival of catheters, as well as the catheter placement, infection incidence, dialysis adequacy were analyzed and evaluated retrospectively. Survival curve was analyzed by Kaplan-Meier method. Median lifetime of the catheters was calculated. Usage difference was examined with log-rank test. Results Cuffed catheters for long-term blood access were implanted in 355 cases of chronic renal failure patients, with a total of 380 implantation including 25 re-implantation. Internal jugular vein was used for the site of catheter implantation in 304 attempts, external jugular vein in 35 and subclavian vein in 40. The mean survival time of the catheter was (32.36±2.16) months (95% CI of 28.1～36.6) and the median survival time (31.0±2.3) months (95% CI of 26.5～35.5). Median survival time of catheter locating in internal jugular vein, external jugular vein and subclavian vein was (31.0±2.8), (30.0±4.0) and (19.0±2.9) months respectively. The survival time of catheter locating in internal jugular vein was significantly longer as compared with that in subclavian vein by Kaplan-Meier(χ2＝4.257，P=0.039). Ending of catheter usage was observed in 113 catheters including death of 60 cases (53.1%), infection of 14 cases (12.4%), successful renal transplantation of 13 cases (11.5%), dysfunction of 13 cases (11.5%), pull-out of 6 cases (6.2%), catheter damage of 4 cases (3.5%) and fistula mature of 2 cases (1.8%). Sixty-three catheter-related infections occurred, among them 21 catheters were removed. No significant difference of dialysis adequacy was found between catheter and fistula group. Conclusions The first choice of long-term indwelling catheter position is internal jugular vein. Main causes of the ending of catheter are death, infection and dysfunction

Objective To evaluate the effect of hemodialysis with fresh frozen plasma-based dialysate (HD-PBD) plus high volume hemofiltration (HVHF) on serum bilirubin removal in patients with liver failure. Methods Fifteen patients with liver failure were enrolled as viewing group who received HD-PBD therapy for 6 hours, then HVHF for 24 hours with the same filter (AV600). Six patients with hyperbilirubinemia treated only with HVHF for 24 hours were as control group. Blood samples from vein and artery end of the filter, plasma-based dialysate from entry and exit of the filter and ultrafiltrate were taken at 5 min（T0）, 2 h (T1), 4 h (T2) and 6 h (T3) during HD-PBD and 5 min（t0）, 6 h (t1), 12 h (t2) and 24 h (t3) during HVHF. Bilirubin levels of dialysate, ultrafiltrate and plasma were measured and quantity of serum bilirubin removed by extracorpomal circulation was calculated. Results (1) The total efficacy of HD-PBD plus HVHF on bilirubin removal was 93.3%, and no obvious adverse reaction occurred. (2) The clearance of serum bilirubin by HD-PBD for 6 hours was significantly higher than that by HVHF for 24 hours (P<0.05). (3) The highest removal quantity of total bilirubin (TB) for dispersion and adsorption was（15.6±5.6） mmol/min and（10.3±3.2）mmol/min at T0 of HD-PBD, which decreased significantly in the next 4~6 hours. (4) TB was mainly removed by adsorption in HVHF and the adsorption removal ratio was 77%～98%, which decreased 12 h later, while ultrafiltration removal quantity was stable. (5) Adsorption quantity and removal ratio of TB by HD-PBD for 6 hours was significantly higher than those by HVHF for 24 hours (P<0.05). (6) Adsorption coefficient of TB by HVHF was obviously degraded after 12 hours in viewing group, but was significantly degraded after 24 hours in control group, and the difference was significant. Conclusions HD-PBD plus HVHF can remove serum bilirubin effectively. Dispersion and adsorption are the major mechanism of serum bilirubin clearance during HD-PBD, which decrease gradually after 4 hours. Adsorption is the major mechanism of serum bilirubin clearance during HVHF with less clearance quantity as compared to HD-PBD.

To evaluate the function of vascular access by measuring blood flow (Qb) and recirculation in hemodialysis patients. Methods Qb and recirculation were measured by Transonic HD02 Monitor 30 minutes after the initiation and 60 minutes before the end of hemodialysis session. When the Qb was too low（Qb<600 ml/min）or too high (Qb>1800 ml/min), the internal diameter and blood flow velocity of vascular access, such as cephalic vein, radial artery and brachial artery, were measured by color Doppler ultrasonography. Results Monitoring of vascular access was successfully performed in 163 of 180 patients. Access recirculation >0 was found in 3 patients (0.02%). The mean Qb was (1010.3±662.6) ml/min. Qb<600 ml/min was found in 40 patients (24.5%), Qb=600~1800 ml/min in 104 patients (63.8%), Qb>1800 ml/min in 19 patients (11.7%). Ten patients presented low Qb measured by color Doppler ultrasonography. Among these 10 patients, stenosis at the inosculated part of blood vessel was found in 4 patients (40%), intima hyperplasia at the site frequently punctured was found in 2 patients (20%), vein shunt was found in 2 patients (20%), and the vascular access was normal in 2 patients (20%). Overall, 80% patients showed abnormalities to a certain extent. The radial arteries in all of the 7 patients whose Qb was too high were dilated. There were significant differences of the diameter of cephalic vein, radial artery and the flow velocity of radial artery, brachial artery between two groups. Conclusions Sensitivity and specificity of ultrasound dilution method in monitoring the vascular access of hemodialysis patients are quite satisfactory. This may be a simple and reliable method for access function surveillance.

Objective To investigate the changes of cardial structure and function, and explore the risk factors of cardiovascular disease in young maintenance hemodialysis (MHD) patients. Methods A total of 98 cases on MHD were enrolled in this study. Among them, 47 patients were young. The cardial structure and function were assessed by echocardiography. The following data were collected: age, gender, ultrafiltration volum, Kt/V, blood pressure, hemoglobin, albumin, lipid, calcium phosphorus product and parathyroid hormone, etc. T test, χ2 test and binary logistic regression analysis were performed for statistics. Results The echocardiography images showed that the incidence of cardial structure and function abnormalities in young MHD patients was 63.8%. The main manifestations were left ventricular hypertrophy, left atrium augmentation and valvular regurgitation, and their prevalence was 61.7%, 38.3% and 34.0% respectively. The prevalence of concentric hypertrophy and eccentric hypertrophy in young MHD patients was 86.2% and 13.8% respectively, which was significantly different as compared with middle-aged and old-aged MHD patients. There were no significant differences of left ventricular hypertrophy, valvular regurgitation, left atrium enlargement, left ventricular diastolic dysfunction, left ventricular systolic dysfunction, pericardial effusion, pulmonary artery hypertension and valvular calcification between young and middle- and old-aged MHD patients. The levels of ultrafiltration volume, systolic blood pressure, serum phosphorus and parathyroid hormone were significantly higher in young MHD patients with cardial abnormality than in those without cardial abnormality. The levels of Kt/V, hemoglobin and serum albumin were significantly lower in young MHD patients with cardial abnormality than in those without cardial abnormality. Logistic regressive analysis revealed that ultrafiltration volume, systolic blood pressure, hemoglobin and parathyroid hormone were important risk factors of cardial abnormality in young MHD patients. The regression equation was as follows: P/(1-P)=exp(-10.82+0.638×UF＋1.298×systolic pressure－0.438×hemoglobin+1.589×PTH). Conclusions The incidence of cardial structure and function abnormality in young MHD patients was quite high. The main cardial lesion patterns of young MHD patients are left ventricular hypertrophy, left atrium augmentation and valvular regurgitation, which are similar to middle-aged and old-aged MHD patients. The type of left ventricular hypertrophy is concentric hypertrophy, which is different from middle-aged and old-aged MHD patients. Ultrafiltration volume, systolic blood pressure, hemoglobin and serum parathyroid hormone may be the important risk factors of cardial structure and function abnormality in young MHD patients.

Objective To investigate the role of extracorporeal membrane oxygenation (ECMO) in the treatment of oleic acid-induced acute respiratory distress syndrome (ARDS) and the role of ECMO combined with high volume hemofiltration (HVHF) in the treatment of ARDS accompanied with acute renal failure in canines. Methods Thirty-two dogs were randomly divided into 4 groups. The model of acute renal failure was established by the ligation of bilateral ureter, meanwhile the model of ARDS by intravenous injection of oleic acid. The models of ARDS were randomly assigned into ARDS respiratory machine group(A) and ECMO treatment group(B). The animals of ARDS accompanied with acute renal failure were randomly assigned into HVHF treatment group(C) and ECMO+HVHF treatment group(D). Blood gas, hemodynamic and biochemical parameters were measured. Results During treatment, PaO2 increased gradually in group B, which was higher than that in group A after 4 hours treatment[（95.58±8.14） vs（82.79±12.37） mm Hg, P < 0.05]. PaO2 in group C was not improved during treatment, while it increased gradually in group D and was signiflcantly higher than that in group C (P < 0.05). Hemodynamic parameters remained stable during treatment. There was a sharp decline of Scr and BUN after hemofiltration treatment[group C:Scr (320.89±65.42) vs (655.04±181.22) μmol/L, BUN (20.42±6.65) vs （41.53±10.59） mmol/L; group D: Scr (334.15±45.97) vs（697.48±101.66） μmol/L, BUN (19.12±6.39) vs（39.10±11.60）mmol/L, all P < 0.01]. Conclusion ECMO can significantly improve the hypoxemia. ECMO combined with HVHF can effectively provide organ support in the treatment of ARDS accompanied with acute renal failure

Objective To explore the role of fibroblast growth factor-23（FGF-23） in phosphorus and vitamin D metabolism of maintenance hemodialysis (MHD) patients. Methods Intact FGF-23 serum level was detected by enzyme-linked immunosorbent assay (ELISA) in 59 MHD patients (MHD group) and twenty healthy people (control group). The level of serum 1, 25-dihydroxy vitamin D [1,25(OH)2VitD] was measured by radioimmunology. At the same time, some other parameters including serum albumin, hemoglobin, creatinine, urea nitrogen, calcium, phosphorus and intact PTH were measured in MHD patients. Results Serum FGF-23 was significantly higher in MHD group than that in control group [(215.23±123.55） vs （28.72±11.49） ng/L, P<0.01]. Moreover, the level of serum 1,25(OH)2VitD was remarkably lower in MHD patients than that in control group [（13.25±8.73） vs（42.24±12.45） μg/L, P<0.01]. By Pearson relativity analysis, serum FGF-23 level was positively correlated with serum phosphorus, calcium, creatinine, intact PTH and duration of hemodialysis (all P<0.05). FGF-23 level was also negatively correlated with age and 1,25(OH)2VitD (P<0.05). No correlations of FGF-23 with gender, blood pressure, albumin, hemoglobin and urea nitrogen were found. Serum phosphorus, calcium, creatinine, intact PTH and 1, 25(OH)2VitD were found to be five independent variables that influenced FGF-23 serum level by multiple regression model. The model accounted for 62% of total variance. (R2= 0.623，P< 0.01). Conclusions The level of serum FGF-23 is significantly higher in MHD patients. Serum phosphorus, calcium, creatinine, intact PTH and 1,25(OH)2VitD are the major regulators that influence FGF-23.

Objective To study the effect of exposure of proximal tubular cells (PTC) to albumin on MMP-2 and MMP-9 expression. Methods Rat proximal tubular cells NRK52E were cultured to reach 70% confluency or complete confluency. Cells were treated with delipidated and non-delipidated bovine serum albumin (dBSA/BSA) ranging from 0.1~1.0 g/L. Conditioned media was harvested at 24 h, 48 h and 72 h. MMP-2 and MMP-9 activities and protein levels were detected by gelatin zymography and Western blot respectively. Results Zymography of 1 g/L BSA exposed media at 72 h, compared with control samples showed activities of MMP-2 and MMP-9 increased by 276% and 176% respectively in sub-confluent NRK52E (P<0.05). Zymography of samples from different time points of 1 g/L BSA exposure showed that activities of MMP-2 and MMP-9 raised by 536% and 148% respectively in sub-confluent NRK52E raised by 212% and 184% respectively in confluent NRK52E by 72 h, compared to 24 h exposure (P<0.05). Zymography at 72 h of 1 g/L BSA containing media of confluent NRK52E, collagenolytic activity of MMP-2 raised by 274% more than that of sub-confluent NRK52E(P<0.05), collagenolytic activity of MMP-9 raised by 45.1% less than that of sub-confluent NRK52E (P<0.05). Results of dBSA exposure were similar to those of BSA exposure. Conclusions Albumin exposure up-regulates MMP-2 and MMP-9 in NRK52E in a dose- and time-dependent manner. Complete confluence (cell junction) inhibits MMP-2 expression, but promotes MMP-9 expression in NRK52E in the state of albumin exposure.

Objective To investigate the renoprotective effect of spironolactone in streptozotocin-induced diabetic rats and explore the possible mechanism. Methods The SD rats were randomly divided into three groups as follows: healthy control rats, diabetic rats, diabetic rats treated with spironolactone. The rats were sacrificed after 30 days treatment. Glomerular morphology was observed by light microscopy. The mRNA expression of TGF-β1 and PAI-1 in renal cortex was measured by RT-PCR. The expression of PAI-1 protein in renal cortex was detected by Western blotting and the concentrations of FN and TGF-β1 in renal glomerulus was analyzed by immunohistochemistry. The activity of antioxidants including T-AOC, SOD, GSH-PX and the level of MDA in renal cortex were measured. Results Compared with diabetic rats, spironolactone could decrease the mRNA and protein expression of PAI-1, TGF-β1 and FN in glomerular area(all P < 0.05 ). Meanwhile, elevated MDA levels [（0.95±0.20）vs（1.23±0.31） nmol/mg，P < 0.05] in the cortex of kidney as well as decreased SOD, GSH-Px, T-AOC activities [（550.19±20.06） vs（509.53±33.25） U/mg，（21.67±2.70） vs（18.91±2.30） U/mg，（1.15±0.21）vs（0.86±0.26） U/mg，respectively, all P < 0.05] in the cortex of kidney were significantly remitted in treatment group. Renal pathologic changes in spironolactone-treated group were also improved. Conclusion Spironolactone ameliorates the glomerular injury presumably via the inhibition of PAI-1 and TGF-β1 expression and the attenuation of oxidative stress in streptozotocin-induced early diabetic injury.

Objective To investigate the impact of the soy protein diet on the early vasculopathy of the 5/6 nephrectomized rats and explore its mechanism. Methods The 5/6 nephrectomized SD rats were used. After operation, 20% casein diet（control group）, 6% casein diet and 6% soy protein diet were delivered respectively. Serum albumin, Scr, BUN, triglyceride, cholesterol and urine albumin were measured before the operation, four, eight and twelve weeks after operation. All the rats were killed after twelve weeks. The pathological changes of aortic arch were evaluated and immunohisttochemistry was used to examine the expression of monocyte chemoattractant protein-1(MCP-1) and lectin-like oxidized low density lipoprotein receptor-1(LOX-1). Results The soy protein diet could lower the urine albumin, Scr, BUN, serum cholesterol and triglyceride. Scr at the 12th week was（111.44 ±5.50） μmol/L in soy group and（172.00±9.54） μmol/L in control group（P<0.01）. There was no significant pathological changes in the aortic arch. The soy protein diet could decrease the expression of the MCP-1（155.68±4.84 vs 132.80±5.67）and the LOX-1（195.48±4.95 vs 167.46±7.62） in the aortic arch. Conclusion The soy protein diet can inhibit the inflammation in aortic intima and delay the progression of early vasculopathy of the 5/6 nephrectomized SD rats.

探讨血管内皮生长因子（VEGF）、基质金属蛋白酶9（MMP-9）及金属蛋白酶1组织抑制剂（TIMP-1）在糖尿病肾病（DN）发病中的作用以及钙离子拮抗剂硝苯地平对肾脏保护作用的机制。 方法 大鼠随机分为3组：健康对照（N）组、DN组和硝苯地平治疗（T）组，每组10只。采用链脲菌素诱发DN大鼠模型，治疗组以硝苯地平控释片15 mg&#8226;kg-1&#8226;d-1干预治疗，治疗第2周和4周，检测大鼠平均动脉压（MAP）、尿蛋白量（24 h）、Scr水平；用免疫组化和Western印迹方法检测大鼠肾脏VEGF、MMP-9、TIMP-1的蛋白表达水平；RT-PCR法检测VEGF、MMP-9、TIMP-1 mRNA的表达。 结果 与N组比较，DN组大鼠尿蛋白量、Scr水平和MAP均显著上升[分别为(78.87±17.62)比(6.30±1.91) mg/24 h、(203.88±18.08)比(84.98±10.09) μmol/L、(141.1±8.7)比(99.8±3.8) mm Hg， P均 < 0.05]；肾组织VEGF、MMP-9、TIMP-1 mRNA和蛋白表达增强（P < 0.05），且MMP-9/TIMP-1比值明显下降（P < 0.05）。与DN组比较，T组尿蛋白量（24 h）[（58.35±10.48） mg]、Scr水平[（165.81±15.86） μmol/L]和MAP[（102.6±4.4） mm Hg]均显著下降（P均 < 0.05）；肾组织VEGF表达下调（P < 0.05），MMP-9、TIMP-1 mRNA和其蛋白表达水平显著增高（分别P < 0.05和P < 0.01），MMP-9/TIMP-1比值显著升高（P < 0.05）。DN大鼠肾组织VEGF mRNA水平与尿蛋白量（24 h）呈正相关（r = 0.748，P < 0.05），与MMP-9/TIMP-1的比值呈负相关（r = -0.711, P < 0.05）。 结论 VEGF、MMP-9和TIMP-1可能参与了DN的发病过程，硝苯地平可能通过影响VEGF、MMP-9及TIMP-1的表达而实现对肾脏的保护作用。