Objective To evaluate the applicability of modified formulas based on plasma creatinine levels in Chinese patients with chronic kidney disease (CKD). Methods A total of 327 CKD patients were investigated. Glomerular filtration rate (GFR) was estimated with Chinese equations and Ruijin equation. The accuracy of estimated GFR was compared with 99mTc-DTPA-GFR(sGFR) in CKD patients. Results Bland-Altman analysis demonstrated that Ruijin equation was more consistent with sGFR than the other equations. But all the equations were not well consistent with sGFR. Linear regression showed that the slopes of Ruijin equation and MDRD-1 equation were closer to the identical line. 15%, 30% and 50% accuracy of Ruijin equation were higher than the other equations. But 30% accuracy of Ruijin equation was still less than 70%. When the accuracy of estimated GFRs was compared with sGFR in different stages of CKD, GFR estimated by Ruijin equation showed good results. Conclusions When plasma creatinine is checked with enzymatic method, modified GFR estimation equations may show great bias in Chinese CKD patients. More clinical trails should be carried out to evaluate and identify the application of modified GFR estimation equations in Chinese patients with CKD.

Objective To investigate the prevalence of chronic kidney diseases (CKD) from inpatients with cerebrovascular diseases in Shanghai district. Methods Inpatients with cerebrovascular diseases from neurology department of five hospitals in Shanghai from Jun. 2007 to Feb. 2008 were recruited . All the patients were respectively diagnosed by brain CT, CTA, MRI, MRA and TCD. Laboratory data included urinary microalbumin-to-creatinine ratio (ACR), routine urinalysis, fasting plasma glucose, 2-hour-postprandial plasma glucose, Scr, uric acid, etc. All the serum creatinine samples were uniformly tested in central laboratory of Shanghai Ruijin Hospital. Glomerular filtration rate (GFR) was estimated by complicated MDRD equation and CKD stage was classified according to K/DOQI guidelines. Results A total of 1014 hospitalized patients with cerebrovascular diseases were enrolled during the observation period, with M/F ratio of 559/455 and mean age of (68.56±12.17) years. Cerebrovascular diseases included ischemic stroke (708 cases), hemorrhagic stroke (197 cases) and transient cerebral ischemic attack (TIA) (109 cases). Microalbuminuria (MAU) was detected in 11.2%, while 24.8% patients had proteinuria. The prevalence of CKD was 47.7%. The percentage of these inpatients in CKD stage 1 to 5 was approximately 6.90%, 14.69%, 21.60%, 2.56% and 1.97% respectively. The Logistic regression model showed that the risk factors of short-term (<30 days) prognosis were albuminuria, hyperglycemia (fast glucose) and anemia. Conclusions The prevalence of CKD in inpatients with cerebrovascular diseases was 47.7% in Shanghai. It is significant to evaluate CKD among patients with cerebrovascular diseases, especially to use the screening of ACR in the early stage.

Objective To investigate the prevalence and associated risk factors of chronic kidney disease (CKD) in adult population receiving body check from urban area of Hefei, Anhui. Methods A total of 33 451 subjects who were older than 20 years and received healthy examination in Health Center of Anhui Provincial Hospital from January 2005 to December 2007 were enrolled in this study. CKD was defined as proteinuria, and/or hematuria, and/or estimated glomerular filtration rate (eGFR) ≤ 60 ml&#8226;min-1&#8226;(1.73 m2)-1. eGFR was estimated by using the simplified MDRD equation. Results The prevalence of proteinuria was 2.74% (95% CI: 2.57%-2.92%）, hematuria 7.67% （95% CI: 7.39%-7.96%）, and reduced eGFR 0.80%（95% CI: 0.71%-0.90%）. 9.92% （95% CI:9.60%-10.25%） subjects had at least one indicator of kidney damage. Age, female, diabetes mellitus, hypertension, and hyperuricemia were independently associated with CKD. Conclusions The prevalence of chronic kidney disease is 9.92% in adult population receiving body check from urban area of Hefei, Anhui. Independent risk factors associated with CKD are age, female, diabetes mellitus, hypertension, and hyperuricemia.

Objective To investigate the clinical significance and histological origin of glomerular epithelial proliferative lesion in patients with focal segmental glomerulosclerosis (FSGS). Methods Seventy-four patients with idiopathic FSGS hospitalized in Peking University First Hospital from Jan. 2000 to Dec.2005 were enrolled in this study. Patients were classified into two groups according to with or without glomerular epithelial proliferative lesion. Estimation of active and chronic pathological scores was carried out using a semi-quantitative grade system by two pathologists. Clinical and pathological characteristics were compared between two groups. Immunohistochemical studies were performed to analyze the histological origin of glomerular epithelial proliferative lesion. Results Thirty-one patients with glomerular epithelial proliferative lesion showed shorter interval from presentation to biopsy（P<0.05）, higher percentage of nephrotic syndrome (NS) （P<0.05）, higher frequency of segmental glomerulosclerosis（P<0.05）, higher pathological active scores（P<0.05） and lower pathological chronic scores（P<0.05）as compared to 43 patients without glomerular epithelial proliferative lesion. Twenty-nine patients were followed up and renal survival rate in patients with glomerular epithelial proliferative lesion (39.7%) was significantly lower than that in patients without glomerular epithelial proliferative lesion (83.3%) (P=0.049). The frequency of glomerular epithelial proliferative lesion and the serum creatinine (Scr) level at biopsy were independent predictors of ESRD（OR value was 1.204，1.008 respectively）. Glomerular epithelial proliferative lesion did not express mature podocyte markers including WT-1 and podocalyxin, but stained positive for PCNA， PAX-2 and CK-8. Conclusions Glomerular epithelial proliferative lesion represents the pathological change of acute stage and active lesion of FSGS, and also may be the pathological marker of severe clinical presentation and worse renal survival. Glomerular epithelial proliferative lesion may be derived from proliferation of parietal epithelial proliferation or de-differentiated podocytes.

Objective To investigate the clinical application of tacrolimus (TAC, FK506) in children with primary nephrotic syndrome (NS). Methods Sixty-five primary NS children received routine or decreased-dosage glucocorticosteroid according to clinical NS types after hospitalization. At the same time, TAC was given orally with the dosage of 0.1 to 0.15 mg/kg, once every 12 hours, for 6 to 24 months. And the serum concentration of TAC was monitored during the course. Results After the treatment of TAC for 1 to 2 months, 65 patients were recovered with gradually reduced urinary protein, rapidly increased serum albumin, and improvement of cholesterol and triglycerides. Total remission rate was 83.1% and onset time was 7 to 54 days. Twelve cases experienced recurrence. Increased CD4, as well as 3/3 or 3/1 TAC genotype, indicated higher remission rate. Various pathological types had different remission rates or ratio, which were as follows: minimal change nephropathy (96.4%), mesangial proliferative glomerulonephritis (90.0%), membranous nephropathy (2/3), membranous proliferative glomerulonephritis (3/5), focal segmental glomerulosclerosis (4/9). The patients would recover in the course of treatment under the conditions of TAC initial dose as 0.1 to 0.15 mg /kg per 12 hours and controlled serum concentration as 5 to 10 g/L. During the treatment, 12 cases appeared gastrointestinal symptoms, mainly as anorexia, nausea and vomiting, 1 abdominal pain, 2 headache, 1 tremor, 1 paresthesia, 3 insomnia, 4 transient increased Scr, 8 slightly increased NAG, 6increased C3 and α-2 macroglobulin. The symptoms disappeared within one week or after stopping TAC. Conclusions TAC is effective in primary NS children, even with abnormal liver function or tuberculosis infection. TAC can also be a substitute to cyclosporine A.

Objective To evaluate the nephroprotective effects of transplanting metanephric mesenchymal cells (MMCs) into the renal subcaspsule of rats with acute tubular necrosis (ATN) induced by gentamicin. Methods MMCs were expanded in culture and immunocytochemistry was used to characterize the cells. After gentamicin-induced ATN, fluorescence-labeled cells were transplanted and traced in kidney tissues by fluorescence microscopy. Serum creatinine(Scr) and N-acetyl-b-D-glucosaminidase(NAG) were tested. Kidney pathology was studied by hematoxylin-eosin staining. Apoptosis was examined by the TUNEL assay.Ki-67 and Bcl-2 expression was examined by immunohistochemistry. Results MMCs were expanded in culture and the phenotype of the cells was vimentin-positive and keratin-negative. Compared with other ATN groups, in the MMCs-treated group, Scr and NAG clearly decreased[14 d Scr: (101.38±20.46) μmol/L vs (248.78±23.15), (252.98±33.52), (229.08±18.18) μmol/L；NAG: (14.83±7.74) U/L vs(33.33±14.88), (29.62±10.54), (30.22±10.94) U/L, P<0.05, respectively]; the histopathologic lesion scores were lower(P<0.05); the Ki-67 antibody and apoptosis of renal tubular epithelial cells were improved or reduced respectively; the expression of Bcl-2 protein was up-regulated(P<0.05). Conclusion The subcapsular transplantation of MMCs can ameliorate renal function and repair kidney injury.

Objective To investigate the effects and molecular mechanism of endoplasmic reticulum stress(ERS) on albumin-induced apoptosis in renal proximal tubular cells(HKCs). Methods Western blot was performed to detect the relationship of the expression of glucose-regulated protein 78(GRP78) and CCAAT/enhancer-binding protein-homologous protein (CHOP) with the action time and concentration of human serum albumin (HSA). Expression levels of CHPO mRNA and protein in HKCs after CHOP siRNA transfection were examined by real-time fluorescence quantitative PCR and Western blot respectively. Annexin-V-FITC and PI double staining cytometry was used to detect the apoptosis of HKCs induced by HSA and influenced by CHOP siRNA. Results (1)After HKCs were stimulatde by 0, 5, 10, 20 g/L albumin for 24 hours respectively, the expression of GRP78, CHOP and HKCs apoptosis were increased with the albumin concentration (P<0.01). After HKCs were stimulated by 20 g/L albumin for 0, 6, 12, 24, 36 hours respectively, the expression of GRP78 was up-regulated at 6-hour, while CHOP and HKCs apoptosis were increased at 12-hour, and significant differences were found among groups (P<0.01). (2) CHOP siRNA significantly inhibited albumin-induced HKC CHOP mRNA and protein expression, as well as HKC apoptosis (P＜0.01). Conclusions Renal tubular cells exposed to high protein load result in ERS. ERS may subsequently lead to tubular damage by activation of pro-apoptosis factor CHOP.

Objective To investigate the effects of losartan on angiotensin(Ang)Ⅱ-induced the generation of oxidative stress and expression of transforming growth factor β1(TGF-β1) in rat proximal tubular epithelial cells and to explore its underlying mechanism. Methods NRK-52E cells, a rat proximal tubular epithelial cell line, were applied to explore the antioxidation and antifibrosis of losartan. The expression of three subunits of nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase, including p47phox, Nox-4, p22phox, and TGF-β1 were determined by real-time RT-PCR and/or Western blot. The generation of reactive oxygen species (ROS) was measured by DCF fluorescence analysis. Superoxide dismutase (SOD) in the supernatant was measured by colorimetric method. Results 10-7 mol/L AngⅡ up-regulated p22prox, p47phox and Nox-4 mRNA and protein expression, and the mRNA increased by 5.57-fold, 5.55-fold and 9.41-fold at 24 h (P<0.01, respectively) and the protein increased by 4.53-fold, 4.17-fold and 6.50-fold at 24 h (P<0.01, respectively) as compared with control. Losartan greatly reduced the mRNA elevation of p22prox, p47phox and Nox-4 by 2.71-fold, 2.18-fold and 5.23-fold(P<0.01, respectively) and reduced the protein elevation by 3.20-fold, 2.30-fold and 4.30-fold(P<0.01, respectively) as compared with control. Losartan also inhibited ROS generation induced by AngⅡ in rat proximal tubular epithelial cells. SOD level in the supernatant was markedly decreased after AngⅡ stimulation, while losartan could increase SOD levels (P<0.01). Furthermore, losartan signficantly inhibited AngⅡ-induced TGF-β1 mRNA up-regulation by 64% (P<0.01). Conclusions Losartan acts as an anti-oxidative and anti-fibrotic agent via the mechanisms of blocking NADPH oxidase-dependent oxidative stress and inhibiting TGF-β1 expression.

Objective To investigate the role of MG-132, a specific dipeptide proteasome inhibitor, on the proliferation, apoptosis and the related proteins in renal interstitial fibroblasts. Methods Renal interstitial fibroblasts (NRK-49F) were induced by transforming growth factor β1(TGF-β1, 5 μg/L) and pre-treated with MG-132(0~5 μmol/L). The cell proliferation was measured with MTT method. Cell cycle and apoptosis were analyzed by flow cytometry. The apoptosis was also analyzed by Annexin V/PI staining and DNA ladder. Expression of p53, p27, p21, caspase-3, Bcl-2 and Bax protein was examined by Western blot. Results TGF-β1(5 μg/L) could stimulate the proliferation of NRK-49F. MG-132(0.25~5 μmol/L) could inhibit TGF-β1-induced proliferation in a dose-dependent manner through G1-arrest. TGF-β1 alone could not induce apoptosis(3.880%±0.365% vs 4.723%±1.582%). But pretreatment of MG-132 (0.1~2.5 μmol/L) could significantly induce apoptosis of TGF-β1-stimulated NRK-49F in a dose-dependent manner. Typical DNA ladder was also confirmed in these two groups in the DNA fragments analysis after being incubated with 2.5 μmol/L MG-132 with or without 5 μg/L TGF-β1. Western blot showed that MG-132 could activate the cell-cycle and apoptosis-related proteins such as p53, p21, caspase-3, Bax and inhibit Bcl-2 in a dose-dependent manner, while expression of p27 remained unchanged. Conclusions Proteasome inhibitor MG-132 can inhibit proliferation and induce the cell apoptosis in renal interstitial fibroblasts stimulated by TGF-β1. The mechanism may be associated to the mediation of p53, p21, caspase-3, Bcl-2 and bax pathways. Proteasome inhibitor may be a new strategy to treat renal interstitial fibrosis.

Objective To investigate the effect and mechanism of prostaglandin E2 (PGE2) in renin regulation at the juxtaglomerular apparatus (JGA). Methods Macula densa cell line (MMDD1) was cultured on the special filter. In the medium on the apical lateral of the cells, low concentration of sodium chloride, chloride and different doses of angiotensin Ⅱ(AngⅡ) were used to stimulate the PGE2 secretion. The PGE2 concentration was tested by ELISA. In the animal experiment, the response of plasma renin activity (PRA) to acute intraperitoneal administration of captopril (30 mg/kg) was determined, in conscious wild-type (WT) and cyclooxygenase COX-2－/－ mice on C57BL/6 genetic backgrounds. PRA was measured in plasma obtained by tail vein puncture. Different concentrations of PGE2 were used to stimulate the renin secretion of primary cultured JGA cells from COX-2－/－ mice and wild type mice. In specific Gsα gene delete mice (low renin producing mice), 24 h urine was collected to test the concentration of PGE2. The COX-2 mRNA and protein of the kidney cortex were observed by real-time PCR and immunohistochemical staining. Results Low chloride could stimulate the PGE2 secretion both at the apical and basement of the macula densa cells. In COX-2－/－ mice, the base PRA and [(378.3±96.4) vs(1115.0±210.0) ng AngI&#8226;ml-1&#8226;h-1，P＝0.0051，n＝10] the renin secretion of primary cultured JGA cells [(153.7±14.7) vs (672.4±129.0) ng AngI&#8226;ml-1&#8226;h-1，P＝0.0162，n＝3] were obviously lower than wild type mice. Captopril could stimulate the PRA of (COX)-2－/－ mice increasing 32.8 times. But AngⅡ had no effect on PGE2 secretion in macula densa cells. In primary cultured JGA cells, the decreasing renin scretion was partly recovered by PGE2 in cells from COX-2－/－ mice. In low renin producing mice, the expression of COX-2 mRNA in the kidney cortex increased by (8.07±1.08) times(n=6, P=0.0022). The COX-2 protein of the kidney cortex and the urine PGE2 increased by several times. Conclusions Low chloride is the primary stimulation messenger of PGE2 secretion in macula densa cells. The PRA in COX-2－/－ mice can be stimulated by angiotensin converting enzyme inhibitor, but the AngⅡ has no direct effect on macula densa cells. When renin production is abolished in JGA cells (Gsα delete mice), COX-2 mRNA and protein up-regulation is observed in kidney cortex and macula densa. PGE2 plays an important role in regulation of renin secretion and renin release in JGA by precise feedback mechanism.

Objective To investigate the protective effect of erythropoietin(EPO) on human renal tubular epithelial-mesenchymal transition（EMT） induced by high glucose. Methods Cultured HK-2 cells were divided into 5 groups: normal control group, osmolarity control group, high glucose group, high glucose with EPO（5 U/ml）group and high glucose with EPO（10 U/ml）group. The mRNA expression of α-SMA, TGF-β1, Smad2, ILK of cells were measured by RT-PCR. The levels of intracellular α-SMA and TGF-β1 protein were measured by immunocytochemistry. Results Compared with the control groups, mRNA expression of α-SMA, TGF-β1, Smad2, ILK and protein expression of α-SMA and TGF-β1 were increased after high glucose treatment（P＜0.01）. Compared with the high glucose group, EPO 5 U/ml or EPO 10 U/ml remarkably down-regulated the expression of α-SMA, TGF-β1, Smad2 and ILK（P＜0.01）. Conclusion EPO can inhibit the progression of EMT and the up-regulation of TGF-β1, Smad2 and ILK induced by high glucose.

Objective To study the effect of astragaloside Ⅳ(AS-Ⅳ) on glucose-induced podocyte adhesion and its possible mechanism. Methods Conditionally immortalized mouse podocytes were treated with 10, 50, 100 mg/L AS-Ⅳ and with 100 mg/L AS-Ⅳ for 3, 6, 12, 24 h. Cell attachment was measured by fluorescence and centrifugation cell adhesion assays, respectively. Expression of α3β1 integrin mRNA and protein was examined by real-time PCR and Western blot. Results High glucose induced a significant reduction in adherent podocytes compared to normal glucose group(P<0.05). AS-Ⅳ improved high glucose-induced podocyte adhesion in a time- and dose-dependent manner. Real-time PCR and Western blot analysis revealed that high glucose-induced down-regulation of α3β1 integrin in podocytes were significantly ameliorated by AS-Ⅳ(P<0.05). Conclusion Astragaloside IV improved high glucose-induced podocyte adhesion which may be mediated through α3β1 integrin up-regulation.