Objective To investigate the mutations of WT1 gene in Chinese patients with Denys-Drash syndrome (DDS). Methods Peripheral blood samples were collected from two children diagnosed clinically as DDS and genomic DNA was isolated from all blood samples using routine method. All coding WT1 exons and their flanking intronic sequences were amplified by polymerase chain reaction(PCR). The amplified PCR products from all individuals were then subjected to automatic DNA sequencing. Results Two types of heterozygous missense mutations in the WT1 gene were：(1)c.1180 C to T transition in exon 9，resulting in replacement of an arginine residue by tryptophan (c.1180C>T， p.R394W).(2)c.1203 C to T transition in exon 9， resulting in replacement of a histidine residue by glutamine(c.1203C>A， p.H401Q). It is the first time that c.1203C>A(p.H401Q) mutation was reported. Conclusions Two mutations including a novel missense mutations(c.1203C>A， p.H401Q) in the WT1 gene are identified in two Chinese children with DDS. Our data also support that the WT1 in DDS locates at c.1180C>T， p.R394W in exon 9.

Objective To analyse the effect of the low osmolar nonionic contrast medium on renal function in patients undergoing coronary angiography and/or percutaneous coronary intervention (PCI). To study the incidence and risk factors of contrast-induced nephropathy (CIN). Methods Three hundred and fifteen patients undergoing PCI or coronary-angiography from December 2004 to March 2005 were enrolled in this study. All patients received low-osmolality nonionic contrast agent. Scr， N-acetyl-β-D-glucosaminidase (NAG) and the osmolality of urine were measured at any time three days before the angiography and at 1， 2 and 6 days post procedure. Multivariate predictors of contrast-induced nephropathy were determined using logistic regression. Result (1)Among the 315 patients， 231 were males and 84 females. The average age was (63.5±11.6) years. Nineteen patients (6.03%)experienced CIN and the incidence of CIN was 6.03%. In those who had both DM and renal insufficiency， the incidence of CIN was 4/8， which was significantly higher than those who had normal renal function and/or DM (P < 0.05，P < 0.01)； (2) In 19 patients who had CIN， the level of urine NAG and Scr at day 1 and 2 post angiography were higher than those before the procedure (P < 0.05)， but they were decreased to normal level at day 6 following angiography. (3)The incidence of previously recorded renal dysfunction was 9/19 in CIN patients and 10.5% (31/296)in non-CIN patients， respectively (P < 0.01). The average contrast volume was (318.4±153.8)ml in CIN group whereas (227.9±121.9) ml in non-CIN group， and significant difference was found between the two groups(P < 0.01). Identified by logistic regression， the volume of contrast agent and pre-existed renal dysfunction were independent risk factors of contrast-induced nephropathy. Conclusions The incidence of CIN in patients who had renal dysfunction combining with DM previously is higher than that in other patients. The urinary NAG indicates early impact of renal tubular function. The volume of contrast and pre-existed renal dysfunction are independent risk factors of contrast-induced nephropathy.

Objective To observe the B- ultrasonic (B-US) renal changes of chronic aristolochic acid nephropathy (CAAN) patients and to determine its value in disease diagnosis. Methods The renal B-US data of 124 CAAN patients were retrospectively studied. The relationship between the B-US characteristics and the renal function was tested. Clinicopathological data of 19 CAAN patients underwent renal biopsy were compared with those of 18 patients with chronic tubulointerstitial nephropathy due to none-aristolochic acid causes (non-AAN-CTIN). Results The characteristics of renal B-US changes in CAAN patients included diminished parenchyma thickness (90.3%)， atrophy of the kidney(62.90%) and asymmetrically shrinked kidneys (17.74%). The renal B-US markers， including the longitude， the volume and the parenchyma thickness， were closely associated with the level of Scr， eGFR and the function of renal tubules (P < 0.05). There was no difference in the severity of impairment of renal function between the CAAN-renal biopsy group and the non-AAN-CTIN group. Histological studies showed that the CAAN-renal biopsy group exhibited more severe tubular epithelial exfoliation and glomerular ischemic shrinkage， while the immune cells infiltrating was much less obvious as compared to the non-AAN-CTIN group(P < 0.05). However， the size of the kidney diminished and the parenchyma was thickened more markedly in the CAAN group as compared to those of non-AAN-CTIN(P < 0.05). Conclusions The CAAN patients exhibit the B-US manifestations including kidney shrink， thinning of renal parenchyma and asymmetrically atrophy of the two kidneys， among which the parenchyma thickness was the earliest abnormal index. Compared with the CTIN patients of the other causes， the CAAN patients showed earlier and more significant kidney atrophy. The B-US examination of CAAN patients can be used as an assisted assessing index of clinical impairment of renal function.

Objective To investigate the effect of ACEI combining with ARB on chronic kidney disease. Methods A randomized control trial was carried out in sixty chronic kidney disease patients， who were divided into ACEI group， ARB group and combined group. The ACEI group received lotensin， and the ARB group received volsartan， while the combined group received therapy of lotensin and volsartan. Clinical data were collected in the beginning， 3rd month， 6th month， 9th month and 12th month. Results Proteinuria of 24 h [(1.08±0.68)g vs.(0.27±0.29)g]and systolic blood pressure [(129±24) mm Hg vs. (116±18) mm Hg] were significantly decreased after 12 month therapy in all groups patients(P < 0.05)， while the GFR[(67.5±30.2)ml/min vs. (69.3±34.6)ml/min]and the level of serum potassium in these patients remained the same after statistical analysis(P > 0.05). Combined therapy had the most noticeable antiproteinuric and blood pressure lowering effect， while renal function improvement，the level of serum potassium and the manifestations of side effects in combined group were similar to those in other two groups(P > 0.05).Conclusion Dual blockage of RAS with ACEI and ARB for long duration has better antiproteinuric and blood pressure lowering effect， and their side effect is mild.

Objective To explore the association of baseline blood pressure level in 1992 and its change from 1992 to 2002 with serum creatinine(Scr) in a cohort of 2740 subjects in Beijing. Methods A baseline investigation on the risk factors of cardiovascular disease was carried out in a natural population of Beijing in 1992. The follow-up survey was conducted in 2002， adding Scr as a new index. Complete data were available for 2740 subjects. Elevation of Scr level was defined as Scr level from 115 μmol/L to 133 μmol/L in male and from 107 μmol/L to 124 μmol/L in female. Renal damage was defined as Scr>133 μmol/L in male and Scr>124 μmol/L in female. These two stages were identified as abnormity of Scr in this study. Results (1) In 2002， the mean level of scr was (87.52±20.33)μmol/L in the samples of 45~74 years old. Male [(96.36±15.92)μmol/L] had a significantly higher level than female [(80.44±21.22)μmol/L]. (2) In this population，the incidence of abnormal Scr was 8.7%. The incidence of male (13.6%) was significantly higher than that of female(4.4%). (3)The incidence of abnormal Scr continually increased with elevation of baseline blood pressure level (P < 0.01). After adjusting for gender， age， BMI and other factors，the odds ratios(OR)of abnormal Scr was 3.89 for BP≥180/110 mm Hg， compared to the group of BP<120/80 mm Hg. (4) The incidence of abnormal Scr was 6.6% in subjects who had normal BP in both 1992 and 2002， whereas the incidence was 12.4% in the subjects who were hypertensive in 1992 but controlled in 2002 and 16.9% in those who were hypertensive both in 1992 and 2002. Conclusion Effective control on hypertension will be helpful to prevent or postpone the elevation of Scr.

Objective To investigate the expression of Nestin， a kind of cytoskeletal protein，in human podocytes. Methods The expression of Nestin in normal human kidney and cultured murine podocytes was determined by immunoelectromicroscope， immunohistochemistry， and immunofluorescence. Co-immunopricipitation (co-IP) was used to detect the proteins that interacted with nestin in podocytes. Results Nestin was selectively expressed in human podocytes and localized in the primary and second processes. The co-immunopricipitation studies demonstrated that Nestin had a physical interaction with vimentin and α-internexin， but not with alpha-actinin 4. Conclusions Nestin is selectively expressed in glomerular podocytes of human kidney，central nerve stem cells，and pancreatic island stem cells as well. Nestin can interact with other cytoskeletal protein in podocyte. This study suggests the potential role of nestin in modulating normal cytoskeletal structure of podocytes.

Objective To study the significance and interaction between HSP72 and paxillin in ischemic renal tubular epithelial cells. Methods To induce cells injury， cells were transiently exposed to metabolic inhibitor for 60 min followed by recovery. The over-expression of wild-type HSP72 was induced by transient heat stress or by infecting opssum kidney(OK) cells with adenovirus containing wild-type human HSP72. Cellular distribution of HSP72 was detected with Western blot. Paxillin distribution was evaluated by immunofluorescence and by its solubility in Triton X-100 extraction solution. Interaction between HSP72 and paxillin was examined by co-immunoprecipitation. Results In controls， ischemia decreased paxillin staining in focal adhesion plaques. Ischemia also shifted both HSP72 and paxillin from the soluble Triton X-100 to the insoluble pool. In contrast， heat stress increased HSP72 content in the Triton X-100 soluble and Triton X-100 insoluble pools，and prevented paxillin redistribution from focal adhesion plaques. Heat stress or viral infection augmented the interaction between HSP72 and paxillin. Conclusion HSP72 as a molecular chaperone preserves cellular focal adhesion at least partially by increasing direct interaction between HSP72 and paxillin.

Objective To investigate the role of volume-sensitive outwardly rectifying (VSOR) chloride channels in mesangial cell apoptosis induced by H2O2. Methods VSOR chloride current was recorded in whole cell configuration. The apoptosis was evaluated by AO/EB staining， transmission electron microscopy， TUNEL staining and caspase-3 activity. Cell volume was measured by Lag-time microphotography. Results Application of 150 μmol/L H2O2 led to activation of VSOR Cl- conductance in mesangial cells. H2O2-induced Cl- current showed phynotypical properties of VSOR Cl- channels， including outward rectification， voltage-dependant inactivation at large positive potentials， sensitiveness to hyperosmolarity，inhibition by VSOR Cl- channel blockers. Moreover， blockage of VSOR Cl- by DIDS(100 μmol/L)， NPPB(10 μmol/L) or niflumic acid(10 μmol/L) rescued mesangial cells from H2O2-induced apoptotic cell death. Treatment for 2 hours with 150 μmol/L H2O2 resulted in significant reduction in cell volume. However， the early-phase alterations in cell volume were markedly abolished by pretreatment with VSOR Cl- channel blockers. Conclusion VSOR Cl- channels are involved in H2O2-induced apoptosis of mesangial cells and its mechanism is associated with the decrease of apoptotic volume (AVD).

Objective To investigate the expression of receptor activator of NF-kappa B (RANK)， its ligand (RANKL) and osteoprotegerin (OPG) in kidney tissue of 5/6 subtotal nephrectomy (STNx) rats， and the effect of valsartan on above expression. Methods Seventy-two male SD rats were divided into STNx control group (n=24)， STNx + valsartan treatment group(n=24) and sham operation group (n=24). In valsartan treatment group， the SD rats received valsartan (15 mg&#8226;kg-1&#8226;d-1)， an angiotensinⅡ type 1(AT1) receptor antagonist， after STNx. At week 4， 8 and 12 after operation， the kidney pathology was examined by light microscopy respectively. RANK， RANKL and OPG expression in kidney tissue was examined by histochemisty， Western blot and RT-PCR. Serum levels of RANKL and OPG were examined by ELISA at week 12. Results (1)At week 12 after operation， the 24-hour urine protein was (13.4±1.2) mg in valsartan group， (19.0±1.5) mg in STNx group and (6.1±0.6) mg in sham operation group (all P < 0.01). (2)Glomerular sclerosis degree in valsartan treatment group was gentler than that in STNx group. (3)In sham operation rat kidneys， RANK and RANKL protein expressed in a few tubules and were absent in glomeruli. RANK and RANKL mRNA expressed in glomeruli in valsartan group and STNx group.Treatment with valsartan manifestly reduced mRNA and protein expression of RANK and RANKL in glomeruli (P < 0.01). There was no differences of OPG expression among these 3 groups. Serum levels of OPG and RANKL were similar in 3 groups at week 12. Conclusions RANK and RANKL may play a role in progressive renal injury following STNx. Inhibition of RANK and RANKL expression may be one of the mechanisms by which AT1 receptor antagonist attenuates renal injury after renal ablation.

Objective To establish the experimental animal model of acute tubular necrosis (ATN) in rats induced by caulis aristolochiae manshuriensis (CAM) containting aristolochic acid (AA) and compare the interventional effects among ligustrazine， prednisone and benazepril. Methods Male SD rats were divided randomly into six groups， 12 rats in each group. Control group， model group， prednisone group， benazepril group， ligustrazineⅠ group and ligustrazineⅡ group were given respectively by gavage with 3 ml/d distilled water，5 g&#8226;kg-1&#8226;d-1 CAM decoction (CAM 2 g/ml， AA 0.54 mg/ml， AA-Ⅰ0.46 mg/ml) for 60 days， then 3 ml/d distilled water， 10 g&#8226;kg-1&#8226;d-1 CAM decoction for 30 days. Two hours after CAM gavage， control group and model group were given with normal saline. Prednisone group， benazepril group， ligustrazine group and ligustrazineⅡ group were given with prednisone 5 mg&#8226;kg-1&#8226;d-1， benazepril 1.7 mg&#8226;kg-1&#8226;d-1， ligustrazine 50 mg&#8226;kg-1&#8226;d-1， ligustrazine 150 mg&#8226;kg-1&#8226;d-1 respectively by gavage for 90 days. Histopathology of kidney tissue was examined after 90 days. Results The renal tissue of control group was normal. Light microscopy of model group revealed patchy vacuolar changes of cells from proximal convoluted tubular epithelium， disorder and loss of brush border，exfoliated epithelial cells in the lumina，exposure of areas of denuded and rupture and thickness and atrophy of tubular basement membrane(TBM)， edema and infiltration of inflammatory cells in the interstitium， focal segmental proliferation of glomerular mesangial cells and increase of mesangial matrix， part thickness of interlobular arterial walls. The above abnormalities of other four groups were significantly attenuated compared to model group. Electron microscopy of model group revealed patchy vacuolar changes and fatty degeneration of cells from proximal convoluted tubular epithelium，swelling of mitonchondria，reduce of organelle， karyorrhexis， apoptosis， infiltration of inflammatory cells (phagocytes and lymphocytes) in the interstitium and infiltration of lymphocytes in the epithelium， thickness of interlobular arterial walls， stenosis of lumina. The above abnormalities of electron microscopy in other four groups were remarkably improved compared to model group as well， especially in ligustrazine Ⅱ group and prednisone group. Conclusions Pathological change of ATN is confirmed in kidney tissue and the rat ATN model induced of AA is successfully established. Benazepril， prednisone and ligustrazine can attenuate the toxic effects by AA. Prednisone and ligustrazine have a better efficacy.

Objective To examine the correlation between metabolic acidosis and malnutrition in maintenance haemodialysis (MHD) patients. Methods Forty-four MHD patients were divided into 3 groups according to plasma bicarbonate concentrations (PHCO3) and pH values. The correlation between metabolic acidosis and nutritional parameters was studied. Results The mean PHCO3 was (19.1±0.9) mmol/L in group A (n=13)， (24.0±1.3) mmol/L in group B (n=22) and (27.1±0.1) mmol/L in group C (n=9). The adequacy of dialysis (Kt/V) was comparable in three groups. As compared with group B， group A had significantly higher body mass index (BMI)， triceps skin fold thickness (TSF)， dietary protein intake (DPI)， normalized protein catabolic rate (nPCR)， Scr， serum K+ and parathyroid hormone (PTH)， meanwhile， group C had significantly lower DPI， nPCR， Scr and albumin. There was no significant difference in plasma inflammatory markers C-reactive protein (CRP) among three groups. There was significant negative correlation of PHCO3 to nPCR (P < 0.01)， DPI (P < 0.01) and Scr (P < 0.01). After 3 months， the correction of metabolic acidosis did not affect nutritional parameters. Conclusion Metabolic acidosis as a result of higher protein intake does not detrimentally affect nutritional status.