Pediatric blood purification requires reliable access to the circulation.Central venous catheters play an important role in the delivery of pediatric blood purification.A central venous noncuffed,nontunneled catheter is the best choice for short-term(less than 3 weeks) blood purification.A cuffed,tunneled catheter is preferable to long term(more than 3 weeks) blood purification.However,there are many complications associated with central venous catheters,such as catheter-induced thrombosis,catheter-related infection,and central vein stenosis.This article reviews the prevention and treatment of complications most frequently occurring with central venous catheters.

Child ; Evidence-Based Medicine ; Humans ; Kidney Diseases

Objective To explore the effect of uric acid (UA) on the rat glomerular mesangial cells (GMCs) and its possible mechanism in vitro. Methods Cultured rat GMCs were treated with various concentrations of UA (50 μmol/L, 100 μmol/L, 300 μmol/L) in the presence or absence of U0126, apocynin, rotenone. The incorporation of 3H-thymidine (3H-TdR) and cell counting were used to measure GMCs proliferation. GMCs cell-cycle was analyzed by flow cytometry. CyclinD1 and cyclin A2 expression were determined by real-time PCR and Western blotting analysis. ERK1/2 phosphorylation was detected by Western blotting. Reactive oxygen species (ROS) was measured by 2, 7-dichlorofluorescein diacetate (DCFDA) fluorescence. Results (1) Uric acid increased GMCs proliferation in dose-dependent manner compared with the control groups, as assessed by 3H-TdR incorporation and cell counting. GMCs proliferation induced by 300 μmol/L uric acid was increased by more than 1.5-fold assessed by both of the methods. (2) Uric acid decreased cell number in G1/G0 phase and increased cell number in S phase in dosedependent manner, as assessed by flow cytometry. (3) Uric acid iuduced cyclin D1 and cyclin A2 expression in dose-dependent manner. (4)Uric acid increased pospho-ERK1/2 in dose-dependent manner and ERK1/2 specific inhibitor U0126 could suppress uric acid-induced cell proliferation.The inhibition percentage of U0126 was 22% and 31% assassed by cell counting and 3H-TdR incorporation, respectively. (5) Uric acid increased ROS production in dose-dependent manner.NADPH oxidase inhibitor apocynin could also significantly inhibit uric acid-induced ROS production, ERK phosphorylation and cell proliferation. In contrast, rotenone had no effect on them.Conclusion Uric acid can stimulate rat GMCs proliferation, partially by the activation of ERK pathway via NADPH oxidase-derived ROS generation.

Objective To elucidate whether Ang Ⅱ indnces the proliferation of mesangial cells through ROS-EGFR-JNK-AP-1 signaling pathway. Methods The incorporation of 3H-thymidine (3H-TdR) and cell count were used to measure mesangial cell (MC) proliferation. ROS production was determined by DCFDA fluorescence. EGFR and JNK activation was assayed by Western blot. Results Ang Ⅱ significantly enhanced ROS production in mesangial cells, which was up-regulated by 2.26 folds of control group after incubation with Ang Ⅱ for 60 min. Ang Ⅱ induced EGFR phosphorylation in dose- and time-dependent manner, with the peak (3.96 folds increase) at 30 min. EGFR phosphorylation was significantly blocked by AT1R antagonist losartan, antioxidant NAC, and NADPH oxidase inhibitor apocynin and DPI. EGFR antagonist AG1478 significantly inhibited Ang Ⅱ-induced mcsangial cell proliferation. Losartan, NAC, apocynin, DPI, and AG1478 ahnost abolished Ang Ⅱ-induced JNK activation. Conclusions ROS-EGFR-JNK-AP-1 signaling pathway is involved in Ang Ⅱ-induced mesangial cell proliferation. Apocynin and AG 1478 may be used as new therapy.

Objective To detect the signaling pathways involved in aldosterone (ALDO)induced mesangial cell (MC) proliferation. Methods The incorporation of 3H-thymidine (3H-TdR)and cell count were used as the measure of mesangial cell (MC) proliferation. Reactive oxygen species (ROS) production was determined by DCFDA fluorescence. Epidermal growth factor receptor (EGFR) activation was assayed by Western blotting. Results ALDO induced MC proliferation.When incubation with 100 nmol/L ALDO for 24 h, the 3H-TdR incorporation and cell number increased by 2.63- and 2.15-fold, respectively. Mineralocorticoid receptor (MR) antagonist EPLE almost completely blocked ALDO-induced MC proliferation (P<0.01), however, glucocorticoid receptor (GR) antagonist RU-486 had no effect on MC proliferation. ALDO increased intracellular ROS production in cultured human MCs. When incubation with ALDO (100 nmol/L) for 60 min,ROS production increased by 2.14-fold. ALDO-induced ROS generation was completely blocked by EPLE as well as mitochondrial complex Ⅰ inhibitor rotenone (P<0.01=, NADPH oxidase inhibitors diphenyleneiodonium sulfate (DPI) and apocynin inhibited ALDO-induced ROS production by 30%to 35% (P<0.05=. In contrast, inhibitors of other oxidant-producing enzymes, including allopurinol,indomethacin, nordihydroguiaretic acid, ketoconazole and G-nitro-L-arginine methyl ester (L-NAME)had no effect on ALDO-induced ROS production. Antioxidant N-acetyl-L-cysteine (NAC) and ROT inhibited ALDO-induced MC proliferation by 75% to 80%, whereas the inhibition of NADPH oxidase inhibitor apocynin and DPI on ALDO-induced MC proliferation was 25% to 30%. ALDO induced EGFR transactivation. When incubation with 100 nmol/L ALDO for 60 min, EGFR phosphorylation was increased by 4.95-fold, which was completely inhibited by EPLE and antioxidant NAC (P<0.01=. NAC and EGFR antagonist AG1478 significantly blocked ALDO-induced MC proliferation (P<0.01=. Conclusions ALDO-induced MC proliferation is mediated by ROS-dependent EGFR transactivation. ALDO-stimulated ROS is mainly generated by mitochondria.

Objective To investigate the role of oxidative stress-dependent Rasextracellular signal-regulated kinase (ERK1/2) signaling in aldosterone (ALDO)-induced mesangial cell proliferation. Methods The incorporation of 3H-thymidine (3H-TdR) and cell count were used as the measure of mesangial cell (MC) proliferation.Western blotting was used to detect the activation of Ki-RasA,c-Raf,MEK1/2,ERK1/2 and PI3K. Results Aldosterone significantly induced human mesangial cell proliferation,and anti-oxidant N-Acetylcysteine (NAC),catalase,and super oxide dismutase (SOD) significantly inhibited ALDO-induced mesangial cell proliferation (P＜0.01,respectively).Stimulation by ALDO for 3 h,Ki-RasA,c-Raf,MEK1/2,and ERK1/2 activity increased by 4.05-, 3.62-, 4.52-, and 3.40-fold compared with control group (P ＜0.01,respectively).NAC almost completely blocked ALDO-induced Ki-RasA,c-Raf,MEK1/2,and ERK1/2 activation (P＜0.01,respectively).Ki-RasA siRNA dose-dependently inhibited Ki-RasA expression, ALDO-induced Ki-RasA activation, and mesangial cell proliferation (P ＜0.01,respectively).c-Raf inhibitor GW5074 and MEK1/2 inhibitor PD98059 also reduced ALDO-induced mesangial cell proliferation by 65％ respectvely (P＜0.01).Ki-RasA siRNA had no effect on ALDO-induced PI3K phosphorylation.Combining LY294002 and PD98059 completely blocked ALDO-induced mesangial cell proliferation (P＜0.01). Conclusions ALDO-induced Ki-RasA-c-Raf-MEK-ERK signaling activation is dependent on reactive oxygen species (ROS) production,which mediates ALDO-induced mesangial cell proliferation.Inhibition of both ERK1/2 and PI3K signaling simultaneously completely blocks ALDO-induced mesangial cell proliferation.

Objective To explore the protection of early autophagy activation on podocyte injury induced by aldosterone.Methods In vitro cultured mouse podocyte clones (MPC5) were treated with aldosterone for 6,12,24,48 h respectively.Apoptosis of podocytes was detected by Annexin V combined with flow cytometry.After 24 h treatment with aldosterone,the existence of apoptotic body and autophagosome was observed by electron microscopy.The protein expressions of LC3,caspase-3 and nephrin were examined by Western blotting.The mRNA expression of Beclin-l was detected by real-time PCR.Results The induction of apoptosis and autophagy by aldosterone in podocytes was in timedependent mannner.After 24 h treatment with aldosterone,the apoptosis was increased by 26.5％ (P ＜ 0.05)and the expression of nephrin was decreased by 28.0％ (P ＜ 0.05) compared to control group.Aldosterone remarkably induced the expression of Beclin-1 at 6 h and promoted the transformation of LC3-Ⅰ to LC3-Ⅱat 12 h (P ＜ 0.05).Compared to simple aldosterone treatment,the apoptosis rate of podocyte was increased by 39.0％ (P ＜ 0.05) and the expression of nephrin was declined by 19.5％ (P ＜ 0.05) after 3-methyladenine (3-MA) pre-treatment.Conclusions Aldosterone can induce autophagy and apoptosis in podocytes.Autophagy occurs earlier (12 h) than apoptosis (24 h).The occurrence of autophagy can inhibit the apoptosis,so the autophagy pathway may be a new research topic of glomerular disease treatment.

OBJECTIVE: To observe whether curcumin could inhibit the accumulation of the collagen IV and fibronectin in the glomeruli in nephrotoxi sera nephritis rats. METHODS: Seventy-two healthy male Sprague-Dawley rats were divided into three groups, with 24 animals in each group. For normal control group, normal saline (0.5 ml/d) was injected through intra-caudal-vein for two days, and at the same time normal saline (0.5 ml/kg) was also daily administered intraperitoneally. For nephrotoxic sera nephritis group, nephrotoxic sera (0.5 ml/d) was injected through the tail vein for two days and dimethyl sulfoxide (0.5 ml/kg) was given intraperitoneally daily. For curcumin group, nephrotoxic sera was injected as above and meanwhile curcumin (50 mg.kg(-1).d(-1)) was administered intraperitoneally every day. Six rats in each group were killed on the 3rd, 7th, 14th and 28th day. Their renal tissue was fixed in 10% formalin for examining the expression of collagen IV and fibronectin. RESULTS: Minimal staining of collagen IV and fibronectin was detected in the basement membrane of normal control rats glomeruli. In the nephrotoxic sera nephritis rats and curcumin treated nephrotoxic sera nephritis rats, the accumulation of collagen IV and fibronectin was increased progressively, with significant difference in the accumulation of collagen IV (P<0.01) between these two groups at the same time points, while the significant difference in fibronectin accumulation (P<0.05) appeared only after the 7th days. CONCLUSION: Curcumin can reduce the accumulation of collagen IV and fibronectin in the glomeruli. Hence we postulated that curcumin might have beneficial effect for retarding glomerulosclerosis.

AIM: To investigate the role of NF-?B/I?B signal pathway in the regulation of (cyclooxygenase-2) (COX-2) expression in human mesangial cells (HMC). METHODS: The PGE_2 concentration in supernatants of HMC was measured by radioimmunoassay. COX-2 mRNA and protein expression were determined by RT-PCR and Western blot. Electrophoretic mobility shift assay (EMSA) and Western blot were used to detect the activity of NF-?B and degradation of I?B. RESULTS: IL-1? significantly upregulated COX-2 expression and PGE_2 production in HMC. Significant up-regulation of NF-?B activation, nuclear translocation of p65 subunit, and degradation of I?B ? and I?B ? were observed in IL-1?-induced HMC. CONCLUSION: Expression of COX-2 in IL-1?-induced HMC is mediated by NF-?B/I?B signal pathway. [

AIM: To investigate the role of CD2AP and F-actin in the pathogenesis of puromycin aminonucleoside nephrosis in rats. METHODS: Puromycin aminonucleoside nephrosis was induced by single intraperitoneal injection of puromycin aminonucleoside (PAN). Renal tissues were studied at 3, 7, 10 and 20 days after PAN injection by means of immunohistochemistry, RT-PCR, Western blotting and fluorescence. RESULTS: At day 3, CD2AP expression in podocytes began to decrease, and significantly decreased at day 7 and 10 (P