Objective    To identify the prevalence of different amyloid types in renal biopsies.    Methods    The renal biopsies of 205 patients diagnosed as renal amyloidosis from January 1990 to December 2011 were reassessed. Immunohistochemistry was performed with a penal of antibodies directed against λ-light chain, κ-light chain, amyloid A, fibrinogen, transthyretin, apolipoprotein A1, and lysozyme. Immune electron microscopy and gene analysis were performed when the results of immunohistochemistry were indeterminate.    Results    Among 205 patients, 190 cases (92.7%) were classified as immunoglobulin light chain amyloidosis (AL), 1 (0.5%) case as amyloid A amyloidosis and 1 (0.5%) case as fibrinogen A α-chain amyloidosis. The amyloid types of remaining 13 (6.3%) cases were undetermined. In the AL patients, the distribution of λ and κ was 6.6:1.    Conclusion    AL is the most common form of renal amyloidosis in China, with a predominant light chain type of λ.

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.
 

Objective    To clarify the clinical significance of visit-to-visit variability in blood pressure (BP) of stage 3-4 chronic kidney disease (CKD) patients with hypertension.    Methods    One hundred and fifty-two cases of stage 3-4 CKD patients with hypertension were enrolled in the study. Variability in BP was defined as the standard deviation (SD) in BP. For each patient, SD and mean BP from BP measurements were calculated at all the visits. Correlations between the decline in estimated glomerular filtration rate (eGFR) and SD in BP were analyzed by multivariable regression.    Results    Visit-to-visit variability in BP was significantly associated with renal function decline (P＜0.05), in addition, baseline eGFR, baseline albuminuria and mean SBP during follow-up were significantly associated with renal function decline as well (all P＜0.05). The percentage of CCBs used in low SD of the SBP group was higher than that in high SD of the SBP (76.1% vs 58.2%, P＜0.05).    Conclusion    Visit-to-visit variability in BP is significantly associated with renal function decline. Drugs which can decrease the variability of blood pressure should be the first choice in the treatment of hypertension.
   

Objective    To determine the relationship between serum soluble Klotho (sKL) level and abdominal aortic calcification in maintenance hemodialysis (MHD) patients.    Methods    One hundred and twenty nine cases of MHD patients were collected prospectively. Serum sKL was detected by ELISA. Abdomen lateral plain were used as a criteria to determine the abdominal aortic calcification. The abdominal aortic calcification score (AAC) was calculated. Logistic regression analysis was used to determine the risk factor of abdominal aortic calcification in MHD patients. The ROC analysis was applied to evaluate the diagnostic value of sKL in abdominal aortic calcification.    Results    Eighty-seven patients had abdominal aortic calcification. The median AAC was 4.0 (0.00, 11.00). The median sKL concentration was 616.29 (378.19，821.61) ng/L and the sKL concentration was negatively correlated with AAC (r＝-0.255, P＜0.05). Risk of moderate to severe abdominal aortic calcification in patients with lowest quartile of the sKL concentration was significantly higher than those with highest quartile (OR＝4.004, 95%CI 1.350-11.826, P＜0.05), even after the adjustment for demographic data, lifestyle factors and biochemical markers (OR＝4.542, 95%CI 1.368-15.081, P＜0.05). Multivariate Logistic regression analysis showed that lower serum sKL level and smoking were independent risk factors for severe calcification of the abdominal aorta. ROC-AUC of serum sKL for severe abdominal aortic calcification was 0.746 (cut off 265.39 ng/L, accuracy 88.5%, specificity 56.2%).    Conclusions    The lower serum sKL is independently associated with severe abdominal aorta calcification. Serum sKL may have diagnostic value for severe abdominal aorta calcification in MHD patients.

Objective To investigate the long-term prognostic factors and the significance of serum cardiac troponin T (cTnT) and C-reactive protein (CRP) in maintenance hemodialysis (MHD) patients. Methods Clinical data of 76 MHD patients in our hospital from January 2002 to January 2003 were retrospectively analyzed. Time and cause of death in the next 10 years were recorded. Survival rate was calculated by Kaplan?Meier and impact factors of long-term prognosis were explored. Significance of cTnT and CRP was elucidated by COX regression analysis. Results CRP was positive in 28 cases (36.8%) and cTnT was positive in 22 cases (28.9%) among 76 patients. The median survival time was 37.9 months, 2-year survival rate was 65.9% and 10-year survival rate was 24.2%. Univariate analysis found positive CRP, positive cTnT, old age, diabetes, cardiocerebrovascular disease, anemia, low serum albumin, Kt/V decline were associated with long-term prognosis. Multivariate analysis showed that increased age (P＝0.010), cardiocerebrovascular disease (P＝0.048), positive cTnT (P＝0.036), positive CRP (P＝0.009) were independent risk factors of the 10-year survival of MHD patients. Ten-year mortality of cardiocerebrovascular diseases in positive cTnT group was not significantly different as compared with negative cTnT group (50.0% vs 35.4%, P＝0.248). But the positive cTnT group had higher 2-year mortality than negative cTnT group (40.9% vs 14.6%, P＝0.015). Mortality of cardiocerebrovascular disease was higher in positive CRP group as compared to negative CRP group at both 2-year and 10-year time (48.1% vs 7.0%, P＝0.000; 66.7% vs 23.3%, P＝0.000). Compared with both negative cTnT and CRP group, both positive cTnT and CRP group had much higher all-cause mortality (92.9% vs 55.6%, P＝0.030), higher mortality of cardiocerebrovascular disease at 10-year (64.3% vs 25.0%, P＝0.009), and higher mortality of cardiocerebrovascular disease at 2-year (57.1% vs 5.6%, P＝0.000). Conclusions Aging, cardiocerebrovascular disease, positive cTnT and positive CRP are independent risk factors of long-term prognosis for MHD patients. Positive cTnT can predict cardiocerebrovascular mortality of MHD patients in 2 years, while positive CRP can predict short- and long-term cardiocerebrovascular mortality. Positive cTnT combined with positive CRP may be more valuable in predicting the poor prognosis of MHD patients.

Objective    To investigate the protective effect of resveratrol (RSV) on  5/6 nephrectomized rats and its mechanism.    Methods    Fifty male SD rats were randomly divided into three groups: sham operated (Sham, n＝10）, 5/6 nephrectomy (Nx, n＝20), and 5/6 nephrectomy＋RSV 20 mg/kg (Nx＋RSV, n＝20). RSV or normal saline was administered one week after 5/6 nephrectomy. Proteinuria was detected every 4 weeks. Serum creatinine and the renal pathological changes were measured after 12 weeks. Immunohistochemisty staining of fibronectin (FN), collagenⅠ, transforming growth factor-β (TGF-β) and connective tissue growth factor (CTGF) were used to analyze the changes of renal fibrosis. Western blotting was used to measure the expression of Smad3, phospho-Smad3, and acety-Smad3. Immunoprecipitation was used to detect the interaction between Sirt1 and Smad3.    Results    Compared with the sham operated rats, subtotal nephrectomy significantly increased proteinuria [(152.14±30.49) mg/24 h vs (25.34±7.54) mg/24 h], serum creatinine[(111.60±21.50) μmol/L vs (53.90±11.59) μmol/L], glomerular sclerosis index (1.56±0.34 vs 0.35±0.08) and the expressions of fibronectin, collagenⅠ, TGF-β and CTGF in renal tissue at 12 weeks after operation (all P＜0.01), and RSV treatment significantly inhibited the above up-regulations (all P＜0.01). Compared with the sham operated rats, subtotal nephrectomy increased the expression of phospholylation and acetylation of Smad3. RSV treatment significantly reduced the expression of acety-Smad3, but had no effect on the phospho-Smad3. Immunoprecipitation revealed a binding effect of Smad3 with Sirt1.    Conclusions    RSV treatment can attenuate proteinuria, protect renal function and inhibit renal fibrosis in 5/6 nephrectomized rats. This renal protective effect is associated with reduced Smad3 acetylation and activation of Sirt1, which suggesting that Sirt1 may be a potential therapeutic target of CKD.

Objective    To investigate the expression of hypoxia-induced factor 1α (HIF-1α)and connective tissue growth factor (CTGF) in the kidneys of unilateral ureteral ligation operation (UUO)model rats and the effect of irbesartan on the expression.    Methods    Thirty healthy adult male  SD rats were randomly divided into 3 groups: sham operation group (n＝10), UUO group (n＝10) and irbesartan group (n＝10, UUO rats treated with irbesartan by lavage 2 days before operation). The rats in sham group and UUO group were treated with equal normal saline by lavage. Renal function, histopathological changes, urinary protein of 24 hours in rats at  week 2 were measured. In situ hybridization and Western blotting were applied to measure the expression of HIF-1α and CTGF.    Results    At week 2, the levels of BUN, Scr  and the expressions of HIF-1α and CTGF were significantly increased in UUO group compared with those in sham group (all P＜0.01). There was significant positive correlation between HIF-1α mRNA and CTGF mRNA (r＝0.697, P＜0.01). Compared with UUO group, the levels of urine protein and Scr were significantly decreased [(103.44±8.76) mg/24 h vs (278.23±26.15) mg/24 h, P＜0.01; (109.15±3.93) μmol/L vs (185.04±13.45) μmol/L P＜0.01], and renal tubulointerstitial  lesion area became smaller (0.28±0.02 vs 0.51±0.05, P＜0.01) in irbesartan group. The expression of HIF-1α mRNA and protein was also significantly decreased after the treatment of irbesartan (all P＜0.01).    Conclusions    The expressions of HIF-1α and CTGF in UUO rats increase significantly. Irbesartan can improve renal fibrosis through down-regulating the expression of HIF-1α and CTGF.

Objective    To investigate the effect of long-term low-dose 1α, 25-dihydroxy  vitamin D3 [1,25(OH)2D3] on rat kidney aquaporin (AQP) 2 expression in 5/6 nephrectomized rats.    Methods    Twelve Sprague-Dawley rats underwent 5/6 nephrectomy surgery were divided into model group (n＝6) and 1,25(OH)2D3 group (n＝6) randomly; sham-operated rats only received the renal capsule stripping (control group, n＝6). Rats in 1,25(OH)2D3 group received 1,25(OH)2D3 (3 ng•100 g-1•d-1, ip) for 24 weeks. Serum and 24-hour urine specimens were collected for measurement of serum creatinine, arginine vasopressin (AVP) and urine protein. Animals were sacrificed at week 24 and kidneys were removed for routine pathological, immunohistochemistry and immunoblotting analysis.    Results    At week 24, plasma AVP level in 1,25(OH)2D3 and model group was much higher than that in control group (all P＜0.05), with no significant differences between the former two groups (P＞0.05). Lower serum creatinine and urinary protein were presented in 1,25(OH)2D3 group compared with the model group rats at week 24 (P＜0.05). Renal medullar fibrosis and inflammatory cell infiltration were improved significantly in 1,25(OH)2D3 group compared with model group (P＜0.01, P＜0.05). Immunohistochemistry analysis revealed abundant AQP2 and p-AQP2 expressed in the renal medulla of sham group, mainly in apical membrane of collecting duct cells. AQP2 expression in model group was down-regulated (P＜0.05) and p-AQP2 expression in apical membrane was reduced. AQP2 expression in 1,25(OH)2D3 group increased compared with model group, with increased p-AQP2 expression in apical membrane. Western blotting revealed same results of these expressions (all P＜0.05). Correlation analysis showed a negative correlation of AQP2 expression with urine volume, medullary fibrosis, and inflammatory cell infiltration (P＜0.05).    Conclusion    Long-term low-dose   1,25(OH)2D3 improves AQP2 expression and response to AVP in collecting duct, which may involve in the anti-polyuric effect of 1,25(OH)2D3 in uremic rat.

Objective    To study the intervention of chenodeoxycholic acid (CDCA) on kidney of high-fructose-fed rats, and investigate the mechanism of CDCA on lipid kidney injury.    Methods    Forty-eight healthy male Wistar rats were randomly divided into three groups: normal control group (n＝16), high fructose group (n＝16) and CDCA group (n＝16). Eight rats were sacrificed at the end of 8 and 16 weeks in each group. BUN, Scr, uric acid (UA), fast glucose, serum lipid concentration, urinary albumin were measured. The triglyceride content of renal cortices was detected. The change of renal histopathology was observed by Periodic acid Schiff staining and electron microscopy. The mRNA expressions of farnesoid X receptor (FXR), small heterodimer partner (SHP), sterol regulatory element-binding protein 1c (SREBP-1c), stearoyl-CoA carboxylase (SCD-1), peroxisome proliferator-activated receptor α (PPARα), acyl coenzyme A oxidase (ACO), transforming growth factor β1 (TGF-β1), type 1 plasminogen activator inhibitor (PAI-1), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and NADPH oxidase 2 (Nox2) were measured by real-time PCR, and the protein expressions of which were analyzed by Western blotting.    Results    Left kidney weight/body weight, triglyceride, very-low- density-lipoprotein and UA in blood were significantly increased in high fructose group (all P＜0.05). Renal function and fast glucose did not change much (P＞0.05). The urinary albumin significantly increased in high fructose group (P＜0.01). The triglyceride content in renal cortex was much more abundant than that in control group (P＜0.01). Renal injuries including mesangial expansion, glomerular basement membrane thickening and podocyte foot process effacement were found in fructose-fed Wistar rats. The gene and protein expressions of FXR and SHP in kidneys of rats fed with high fructose were significantly down-regulated (all P＜0.01). The gene and protein expressions of SREBP-1c and SCD-1 in kidneys of rats fed with high fructose were significantly up-regulated (all P＜0.01). The gene and protein expressions of PPARα and ACO in kidneys of rats fed with high fructose were significantly down-regulated (all P＜0.01). TGF-β1, PAI-1, TNF-α, IL-6 and Nox2 in kidneys of rats fed with high fructose were significantly up-regulated (all P＜0.01). The levels of these changes were prominent with the extention of time.  CDCA treatment could reverse these changes (all P＜0.05).    Conclusions    High-fructose feeding can lead to kidney injury in rats. CDCA enhances lipid anabolism, attenuates lipid catabolism, by activating FXR, down-regulating SREBP-1c and SCD-1, up-regulating PPARα and ACO, subsequently decreases profibrotic growth factors，improves renal inflammation, and protects kidney against oxidative stress.

Objective    To compared two classical rat models of nephrotic syndrome and to provide some reference data to researchers.    Methods    Thirty male SD rats were randomly divided into control group, puromycin aminonucleoside-induced nephrotic syndrome (PAN) group and adriamycin-induced nephrotic syndrome (ADR) group. The body weight, twenty four hour proteinuria level, serum albumin concentration, cholesterol concentration, creatinine and urea concentration were measured. The renal pathology change was evaluated. The drug toxic effects, administration methods and the costs were also compared.    Results    There was no significant difference in body weight and hair color between control group and PAN group. Compared to control group, the body weight of the rats significantly decreased at day 15 and day 21 in ADR group (P＜0.01), accompanied by epilation and diarrhea. Compared to control group, the 24-hour urinary protein levels increased significantly at day 10 (P＜0.01), day 15 (P＜0.01), and  reached the peak level at day 15 (P＜0.01), day 21 (P＜0.01) in PAN group and ADR group respectively. Compared to control group, the serum albumin concentration decreased significantly at day 10 (P＜0.01), and return to normal level at day 15. The serum cholesterol concentration was increased significantly at day 10 (P＜0.01) and return to normal at day 15 in PAN group. Compared to control group, the serum albumin concentration was decreased significantly at day 15 (P＜0.05) and return to normal at day 21 in ADR group. No significant difference of serum creatinine and serum urea nitrogen levels were found among three groups. Compared to control group, the width of foot process increased significantly at day10 (P＜0.01) and day 15 (P＜0.05) in PAN group and ADR group respectively. To successfully induce a nephrotic rat model (per 100 g), the cost of PAN group was 3.1 times of ADR group (578.10 yuan vs 186.94 yuan).    Conclusions    Nephrotic syndrome can be induced by both PAN and ADR. The administration of PAN via intraperitoneal injection is more convenient as compared to ADR via tail intravenous injection. Compared to ADR, PAN can induce nephrotic syndrome model more rapidly, with more consistent detection index, and less toxic effects, but its cost is more expensive.
  

Objective     To explore the effect of suramin on the epithelial-mesenchymal transition (EMT) and the excretion of transforming growth factor-β1 (TGF-β1) in peritoneal mesothelial cells (PMCs) induced by high concentrations of glucose solution (GS).    Methods    Cultured PMCs were divided into three groups: (1) normal control group; (2) GS-treated group: cells were treated with 1.5%, 2.5%, 4.25% GS for 12 h, 24 h, 48 h, respectively; (3) Suramin-treated group: PMCs cultured with 4.25% GS were exposed to different doses of suramin (25, 50, 100 μmol/L) for 48 h. Expression levels of α-smooth muscle actin (α-SMA) and E-cadherin were detected by Western blotting and the concentration of TGF-β1 in the culture supernatant was determined by ELISA.    Results     Compared with normal control group, GS-treated PMCs exhibited a time-dependent increase in the  expression of α-SMA, and decrease in the expression of E-cadherin. GS also stimulated PMCs to secrete TGF-β1. In the presence of suramin, GS-induced α-SMA expression and TGF-β1 production were reduced,            E-cadherin expression was increased.    Conclusions    Suramin can inhibit high glucose-induced EMT of PMCs by down-regulating the expression of TGF-β1. Suramin may be a novel therapeutic agent for the treatment of peritoneal fibrosis.